2026-02-17 11:23:10 +01:00
23 changed files with 2029 additions and 18 deletions
--- a/.claude/settings.local.json
+++ b/.claude/settings.local.json
@@ -0,0 +1,13 @@
+{
+  "permissions": {
+    "allow": [
+      "WebSearch",
+      "WebFetch(domain:github.com)",
+      "WebFetch(domain:www.gnu.org)",
+      "Bash(go run:*)",
+      "Bash(go build:*)",
+      "Bash(go doc:*)",
+      "Bash(go test:*)"
+    ]
+  }
+}
--- a/app_mail.go
+++ b/app_mail.go
@@ -73,6 +73,47 @@ func (a *App) ReadMSGOSS(filePath string) (*internal.EmailData, error) {
 	return internal.ReadMsgFile(filePath)
 }

+// DetectEmailFormat inspects the file's binary content to determine its format,
+// regardless of the file extension. Returns "eml", "msg", or "unknown".
+//
+// Parameters:
+//   - filePath: Absolute path to the file to inspect
+//
+// Returns:
+//   - string: Detected format ("eml", "msg", or "unknown")
+//   - error: Any file I/O errors
+func (a *App) DetectEmailFormat(filePath string) (string, error) {
+	format, err := internal.DetectEmailFormat(filePath)
+	return string(format), err
+}
+
+// ReadAuto automatically detects the email file format from its binary content
+// and delegates to the appropriate reader (ReadEML/ReadPEC for EML, ReadMSG for MSG).
+//
+// Parameters:
+//   - filePath: Absolute path to the email file
+//
+// Returns:
+//   - *internal.EmailData: Parsed email data
+//   - error: Any parsing or detection errors
+func (a *App) ReadAuto(filePath string) (*internal.EmailData, error) {
+	format, err := internal.DetectEmailFormat(filePath)
+	if err != nil {
+		return nil, err
+	}
+
+	switch format {
+	case internal.FormatMSG:
+		return internal.ReadMsgFile(filePath)
+	default: // FormatEML or FormatUnknown – try PEC first, fall back to plain EML
+		data, err := internal.ReadPecInnerEml(filePath)
+		if err != nil {
+			return internal.ReadEmlFile(filePath)
+		}
+		return data, nil
+	}
+}
+
 // ShowOpenFileDialog displays the system file picker dialog filtered for email files.
 // This allows users to browse and select .eml or .msg files to open.
 //
--- a/backend/utils/mail/eml_reader.go
+++ b/backend/utils/mail/eml_reader.go
@@ -146,6 +146,9 @@ func ReadEmlFile(filePath string) (*EmailData, error) {
 		})
 	}

+	// Expand any TNEF (winmail.dat) attachments into their contained files.
+	attachments = expandTNEFAttachments(attachments)
+
 	isPec := hasDatiCert && hasSmime

 	// Format From
@@ -267,6 +270,9 @@ func ReadPecInnerEml(filePath string) (*EmailData, error) {
 		})
 	}

+	// Expand any TNEF (winmail.dat) attachments into their contained files.
+	attachments = expandTNEFAttachments(attachments)
+
 	isPec := hasDatiCert && hasSmime

 	// Format From
--- a/backend/utils/mail/format_detector.go
+++ b/backend/utils/mail/format_detector.go
@@ -0,0 +1,47 @@
+package internal
+
+import (
+	"bytes"
+	"os"
+)
+
+// EmailFormat represents the detected format of an email file.
+type EmailFormat string
+
+const (
+	FormatEML     EmailFormat = "eml"
+	FormatMSG     EmailFormat = "msg"
+	FormatUnknown EmailFormat = "unknown"
+)
+
+// msgMagic is the OLE2/CFB compound file header signature used by .msg files.
+var msgMagic = []byte{0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1}
+
+// DetectEmailFormat identifies the email file format by inspecting the file's
+// binary magic bytes, regardless of the file extension.
+//
+// Supported formats:
+//   - "msg": Microsoft Outlook MSG (OLE2/CFB compound file)
+//   - "eml": Standard MIME email (RFC 5322)
+//   - "unknown": Could not determine format
+func DetectEmailFormat(filePath string) (EmailFormat, error) {
+	f, err := os.Open(filePath)
+	if err != nil {
+		return FormatUnknown, err
+	}
+	defer f.Close()
+
+	buf := make([]byte, 8)
+	n, err := f.Read(buf)
+	if err != nil || n < 1 {
+		return FormatUnknown, nil
+	}
+
+	// MSG files start with the OLE2 Compound File Binary magic bytes.
+	if n >= 8 && bytes.Equal(buf[:8], msgMagic) {
+		return FormatMSG, nil
+	}
+
+	// EML files are plain-text MIME messages; assume EML for anything else.
+	return FormatEML, nil
+}
--- a/backend/utils/mail/tnef_diag2_test.go
+++ b/backend/utils/mail/tnef_diag2_test.go
@@ -0,0 +1,58 @@
+package internal
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/teamwork/tnef"
+)
+
+func TestTNEFAttributes(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	f, _ := os.Open(testFile)
+	defer f.Close()
+
+	outerEmail, _ := Parse(f)
+	var innerData []byte
+	for _, att := range outerEmail.Attachments {
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			innerData, _ = io.ReadAll(att.Data)
+			break
+		}
+	}
+
+	innerEmail, _ := Parse(bytes.NewReader(innerData))
+	for _, att := range innerEmail.Attachments {
+		data, _ := io.ReadAll(att.Data)
+		if strings.ToLower(att.Filename) != "winmail.dat" {
+			continue
+		}
+
+		decoded, _ := tnef.Decode(data)
+		fmt.Printf("MAPI Attributes (%d):\n", len(decoded.Attributes))
+		for _, attr := range decoded.Attributes {
+			dataPreview := fmt.Sprintf("%d bytes", len(attr.Data))
+			if len(attr.Data) < 200 {
+				dataPreview = fmt.Sprintf("%q", attr.Data)
+			}
+			fmt.Printf("  Name=0x%04X  Data=%s\n", attr.Name, dataPreview)
+		}
+
+		// Check Body/BodyHTML from TNEF data struct fields
+		fmt.Printf("\nBody len: %d\n", len(decoded.Body))
+		fmt.Printf("BodyHTML len: %d\n", len(decoded.BodyHTML))
+
+		// Check attachment details
+		for i, ta := range decoded.Attachments {
+			fmt.Printf("Attachment[%d]: title=%q dataLen=%d\n", i, ta.Title, len(ta.Data))
+		}
+	}
+}
--- a/backend/utils/mail/tnef_diag3_test.go
+++ b/backend/utils/mail/tnef_diag3_test.go
@@ -0,0 +1,67 @@
+package internal
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/teamwork/tnef"
+)
+
+func TestTNEFAllSizes(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	f, _ := os.Open(testFile)
+	defer f.Close()
+
+	outerEmail, _ := Parse(f)
+	var innerData []byte
+	for _, att := range outerEmail.Attachments {
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			innerData, _ = io.ReadAll(att.Data)
+			break
+		}
+	}
+
+	innerEmail, _ := Parse(bytes.NewReader(innerData))
+	for _, att := range innerEmail.Attachments {
+		data, _ := io.ReadAll(att.Data)
+		if strings.ToLower(att.Filename) != "winmail.dat" {
+			continue
+		}
+
+		decoded, _ := tnef.Decode(data)
+
+		totalAttrSize := 0
+		for _, attr := range decoded.Attributes {
+			totalAttrSize += len(attr.Data)
+			fmt.Printf("  Attr 0x%04X: %d bytes\n", attr.Name, len(attr.Data))
+		}
+
+		totalAttSize := 0
+		for _, ta := range decoded.Attachments {
+			totalAttSize += len(ta.Data)
+		}
+
+		fmt.Printf("\nTotal TNEF data: %d bytes\n", len(data))
+		fmt.Printf("Total attribute data: %d bytes\n", totalAttrSize)
+		fmt.Printf("Total attachment data: %d bytes\n", totalAttSize)
+		fmt.Printf("Accounted: %d bytes\n", totalAttrSize+totalAttSize)
+		fmt.Printf("Missing: %d bytes\n", len(data)-totalAttrSize-totalAttSize)
+
+		// Try raw decode to check for nested message/attachment objects
+		fmt.Printf("\nBody: %d, BodyHTML: %d\n", len(decoded.Body), len(decoded.BodyHTML))
+
+		// Check attachment[0] content
+		if len(decoded.Attachments) > 0 {
+			a0 := decoded.Attachments[0]
+			fmt.Printf("\nAttachment[0] Title=%q Data (hex): %x\n", a0.Title, a0.Data)
+		}
+	}
+}
--- a/backend/utils/mail/tnef_diag4_test.go
+++ b/backend/utils/mail/tnef_diag4_test.go
@@ -0,0 +1,78 @@
+package internal
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+)
+
+func TestTNEFRawScan(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	f, _ := os.Open(testFile)
+	defer f.Close()
+
+	outerEmail, _ := Parse(f)
+	var innerData []byte
+	for _, att := range outerEmail.Attachments {
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			innerData, _ = io.ReadAll(att.Data)
+			break
+		}
+	}
+
+	innerEmail, _ := Parse(bytes.NewReader(innerData))
+	for _, att := range innerEmail.Attachments {
+		data, _ := io.ReadAll(att.Data)
+		if strings.ToLower(att.Filename) != "winmail.dat" {
+			continue
+		}
+
+		fmt.Printf("TNEF raw size: %d bytes\n", len(data))
+
+		// Verify signature
+		if len(data) < 6 {
+			t.Fatal("too short")
+		}
+		sig := binary.LittleEndian.Uint32(data[0:4])
+		key := binary.LittleEndian.Uint16(data[4:6])
+		fmt.Printf("Signature: 0x%08X  Key: 0x%04X\n", sig, key)
+
+		offset := 6
+		attrNum := 0
+		for offset < len(data) {
+			if offset+9 > len(data) {
+				fmt.Printf("  Truncated at offset %d\n", offset)
+				break
+			}
+
+			level := data[offset]
+			attrID := binary.LittleEndian.Uint32(data[offset+1 : offset+5])
+			attrLen := binary.LittleEndian.Uint32(data[offset+5 : offset+9])
+
+			levelStr := "MSG"
+			if level == 0x02 {
+				levelStr = "ATT"
+			}
+
+			fmt.Printf("  [%03d] offset=%-8d level=%s id=0x%08X len=%d\n",
+				attrNum, offset, levelStr, attrID, attrLen)
+
+			// Move past: level(1) + id(4) + len(4) + data(attrLen) + checksum(2)
+			offset += 1 + 4 + 4 + int(attrLen) + 2
+
+			attrNum++
+			if attrNum > 200 {
+				fmt.Println("  ... stopping at 200 attributes")
+				break
+			}
+		}
+	}
+}
--- a/backend/utils/mail/tnef_diag5_test.go
+++ b/backend/utils/mail/tnef_diag5_test.go
@@ -0,0 +1,241 @@
+package internal
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+)
+
+func TestTNEFMapiProps(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	f, _ := os.Open(testFile)
+	defer f.Close()
+
+	outerEmail, _ := Parse(f)
+	var innerData []byte
+	for _, att := range outerEmail.Attachments {
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			innerData, _ = io.ReadAll(att.Data)
+			break
+		}
+	}
+
+	innerEmail, _ := Parse(bytes.NewReader(innerData))
+	for _, att := range innerEmail.Attachments {
+		rawData, _ := io.ReadAll(att.Data)
+		if strings.ToLower(att.Filename) != "winmail.dat" {
+			continue
+		}
+
+		// Navigate to the first attachment's attAttachment (0x9005) block
+		// From the raw scan: [011] offset=12082 + header(9bytes) = 12091 for data
+		// Actually let's re-scan to find it properly
+		offset := 6
+		for offset < len(rawData) {
+			if offset+9 > len(rawData) {
+				break
+			}
+			level := rawData[offset]
+			attrID := binary.LittleEndian.Uint32(rawData[offset+1 : offset+5])
+			attrLen := int(binary.LittleEndian.Uint32(rawData[offset+5 : offset+9]))
+			dataStart := offset + 9
+
+			// attAttachment = 0x00069005, we want the FIRST one (for attachment group 1)
+			if level == 0x02 && attrID == 0x00069005 && attrLen > 1000 {
+				fmt.Printf("Found attAttachment at offset %d, len=%d\n", offset, attrLen)
+				parseMapiProps(rawData[dataStart:dataStart+attrLen], t)
+				break
+			}
+
+			offset += 9 + attrLen + 2
+		}
+	}
+}
+
+func parseMapiProps(data []byte, t *testing.T) {
+	if len(data) < 4 {
+		t.Fatal("too short for MAPI props")
+	}
+
+	count := binary.LittleEndian.Uint32(data[0:4])
+	fmt.Printf("MAPI property count: %d\n", count)
+
+	offset := 4
+	for i := 0; i < int(count) && offset+4 <= len(data); i++ {
+		propTag := binary.LittleEndian.Uint32(data[offset : offset+4])
+		propType := propTag & 0xFFFF
+		propID := (propTag >> 16) & 0xFFFF
+		offset += 4
+
+		// Handle named properties (ID >= 0x8000)
+		if propID >= 0x8000 {
+			// Skip GUID (16 bytes) + kind (4 bytes)
+			if offset+20 > len(data) {
+				break
+			}
+			kind := binary.LittleEndian.Uint32(data[offset+16 : offset+20])
+			offset += 20
+			if kind == 0 { // MNID_ID
+				offset += 4 // skip NamedID
+			} else { // MNID_STRING
+				if offset+4 > len(data) {
+					break
+				}
+				nameLen := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+				offset += 4 + nameLen
+				// Pad to 4-byte boundary
+				if nameLen%4 != 0 {
+					offset += 4 - nameLen%4
+				}
+			}
+		}
+
+		var valueSize int
+		switch propType {
+		case 0x0002: // PT_SHORT
+			valueSize = 4 // padded to 4
+		case 0x0003: // PT_LONG
+			valueSize = 4
+		case 0x000B: // PT_BOOLEAN
+			valueSize = 4
+		case 0x0040: // PT_SYSTIME
+			valueSize = 8
+		case 0x001E: // PT_STRING8
+			if offset+4 > len(data) {
+				return
+			}
+			// count=1, then length, then data padded
+			cnt := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(data) {
+					return
+				}
+				slen := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+				offset += 4
+				strData := ""
+				if offset+slen <= len(data) && slen < 200 {
+					strData = string(data[offset : offset+slen])
+				}
+				fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X STRING8 len=%d val=%q\n", i, propID, propType, slen, strData)
+				offset += slen
+				if slen%4 != 0 {
+					offset += 4 - slen%4
+				}
+			}
+			continue
+		case 0x001F: // PT_UNICODE
+			if offset+4 > len(data) {
+				return
+			}
+			cnt := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(data) {
+					return
+				}
+				slen := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+				offset += 4
+				fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X UNICODE len=%d\n", i, propID, propType, slen)
+				offset += slen
+				if slen%4 != 0 {
+					offset += 4 - slen%4
+				}
+			}
+			continue
+		case 0x0102: // PT_BINARY
+			if offset+4 > len(data) {
+				return
+			}
+			cnt := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(data) {
+					return
+				}
+				blen := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+				offset += 4
+				fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X BINARY len=%d\n", i, propID, propType, blen)
+				offset += blen
+				if blen%4 != 0 {
+					offset += 4 - blen%4
+				}
+			}
+			continue
+		case 0x000D: // PT_OBJECT
+			if offset+4 > len(data) {
+				return
+			}
+			cnt := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(data) {
+					return
+				}
+				olen := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+				offset += 4
+				fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X OBJECT len=%d\n", i, propID, propType, olen)
+				// Peek at first 16 bytes (GUID)
+				if offset+16 <= len(data) {
+					fmt.Printf("        GUID: %x\n", data[offset:offset+16])
+				}
+				offset += olen
+				if olen%4 != 0 {
+					offset += 4 - olen%4
+				}
+			}
+			continue
+		case 0x1003: // PT_MV_LONG
+			if offset+4 > len(data) {
+				return
+			}
+			cnt := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+			offset += 4
+			fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X MV_LONG count=%d\n", i, propID, propType, cnt)
+			offset += cnt * 4
+			continue
+		case 0x1102: // PT_MV_BINARY
+			if offset+4 > len(data) {
+				return
+			}
+			cnt := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+			offset += 4
+			totalSize := 0
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(data) {
+					return
+				}
+				blen := int(binary.LittleEndian.Uint32(data[offset : offset+4]))
+				offset += 4
+				totalSize += blen
+				offset += blen
+				if blen%4 != 0 {
+					offset += 4 - blen%4
+				}
+			}
+			fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X MV_BINARY count=%d totalSize=%d\n", i, propID, propType, cnt, totalSize)
+			continue
+		default:
+			fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X (unknown type)\n", i, propID, propType)
+			return
+		}
+
+		if valueSize > 0 {
+			if propType == 0x0003 && offset+4 <= len(data) {
+				val := binary.LittleEndian.Uint32(data[offset : offset+4])
+				fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X LONG val=%d (0x%X)\n", i, propID, propType, val, val)
+			} else {
+				fmt.Printf("  [%03d] PropID=0x%04X Type=0x%04X size=%d\n", i, propID, propType, valueSize)
+			}
+			offset += valueSize
+		}
+	}
+}
--- a/backend/utils/mail/tnef_diag6_test.go
+++ b/backend/utils/mail/tnef_diag6_test.go
@@ -0,0 +1,209 @@
+package internal
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/teamwork/tnef"
+)
+
+func TestTNEFNestedMessage(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	f, _ := os.Open(testFile)
+	defer f.Close()
+
+	outerEmail, _ := Parse(f)
+	var innerData []byte
+	for _, att := range outerEmail.Attachments {
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			innerData, _ = io.ReadAll(att.Data)
+			break
+		}
+	}
+
+	innerEmail, _ := Parse(bytes.NewReader(innerData))
+	for _, att := range innerEmail.Attachments {
+		rawData, _ := io.ReadAll(att.Data)
+		if strings.ToLower(att.Filename) != "winmail.dat" {
+			continue
+		}
+
+		// Navigate to attAttachment (0x9005) for first attachment
+		offset := 6
+		for offset < len(rawData) {
+			if offset+9 > len(rawData) {
+				break
+			}
+			level := rawData[offset]
+			attrID := binary.LittleEndian.Uint32(rawData[offset+1 : offset+5])
+			attrLen := int(binary.LittleEndian.Uint32(rawData[offset+5 : offset+9]))
+			dataStart := offset + 9
+
+			if level == 0x02 && attrID == 0x00069005 && attrLen > 1000 {
+				mapiData := rawData[dataStart : dataStart+attrLen]
+
+				// Parse MAPI props to find PR_ATTACH_DATA_OBJ (0x3701)
+				embeddedData := extractPRAttachDataObj(mapiData)
+				if embeddedData == nil {
+					t.Fatal("could not find PR_ATTACH_DATA_OBJ")
+				}
+
+				fmt.Printf("PR_ATTACH_DATA_OBJ total: %d bytes\n", len(embeddedData))
+				fmt.Printf("First 32 bytes after GUID: %x\n", embeddedData[16:min2(48, len(embeddedData))])
+
+				// Check if after the 16-byte GUID there's a TNEF signature
+				afterGuid := embeddedData[16:]
+				if len(afterGuid) >= 4 {
+					sig := binary.LittleEndian.Uint32(afterGuid[0:4])
+					fmt.Printf("Signature after GUID: 0x%08X (TNEF=0x223E9F78)\n", sig)
+
+					if sig == 0x223E9F78 {
+						fmt.Println("It's a nested TNEF stream!")
+						decoded, err := tnef.Decode(afterGuid)
+						if err != nil {
+							fmt.Printf("Nested TNEF decode error: %v\n", err)
+						} else {
+							fmt.Printf("Nested Body: %d bytes\n", len(decoded.Body))
+							fmt.Printf("Nested BodyHTML: %d bytes\n", len(decoded.BodyHTML))
+							fmt.Printf("Nested Attachments: %d\n", len(decoded.Attachments))
+							for i, na := range decoded.Attachments {
+								fmt.Printf("  [%d] %q (%d bytes)\n", i, na.Title, len(na.Data))
+							}
+							fmt.Printf("Nested Attributes: %d\n", len(decoded.Attributes))
+						}
+					} else {
+						// Try as raw MAPI attributes (no TNEF wrapper)
+						fmt.Printf("Not a TNEF stream. First byte: 0x%02X\n", afterGuid[0])
+						// Check if it's a count of MAPI properties
+						if len(afterGuid) >= 4 {
+							propCount := binary.LittleEndian.Uint32(afterGuid[0:4])
+							fmt.Printf("First uint32 (possible prop count): %d\n", propCount)
+						}
+					}
+				}
+				break
+			}
+
+			offset += 9 + attrLen + 2
+		}
+	}
+}
+
+func extractPRAttachDataObj(mapiData []byte) []byte {
+	if len(mapiData) < 4 {
+		return nil
+	}
+	count := int(binary.LittleEndian.Uint32(mapiData[0:4]))
+	offset := 4
+
+	for i := 0; i < count && offset+4 <= len(mapiData); i++ {
+		propTag := binary.LittleEndian.Uint32(mapiData[offset : offset+4])
+		propType := propTag & 0xFFFF
+		propID := (propTag >> 16) & 0xFFFF
+		offset += 4
+
+		// Handle named props
+		if propID >= 0x8000 {
+			if offset+20 > len(mapiData) {
+				return nil
+			}
+			kind := binary.LittleEndian.Uint32(mapiData[offset+16 : offset+20])
+			offset += 20
+			if kind == 0 {
+				offset += 4
+			} else {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				nameLen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4 + nameLen
+				if nameLen%4 != 0 {
+					offset += 4 - nameLen%4
+				}
+			}
+		}
+
+		switch propType {
+		case 0x0002: // PT_SHORT
+			offset += 4
+		case 0x0003: // PT_LONG
+			offset += 4
+		case 0x000B: // PT_BOOLEAN
+			offset += 4
+		case 0x0040: // PT_SYSTIME
+			offset += 8
+		case 0x001E, 0x001F: // PT_STRING8, PT_UNICODE
+			if offset+4 > len(mapiData) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				slen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4 + slen
+				if slen%4 != 0 {
+					offset += 4 - slen%4
+				}
+			}
+		case 0x0102: // PT_BINARY
+			if offset+4 > len(mapiData) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				blen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4 + blen
+				if blen%4 != 0 {
+					offset += 4 - blen%4
+				}
+			}
+		case 0x000D: // PT_OBJECT
+			if offset+4 > len(mapiData) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				olen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4
+				if propID == 0x3701 {
+					// This is PR_ATTACH_DATA_OBJ!
+					return mapiData[offset : offset+olen]
+				}
+				offset += olen
+				if olen%4 != 0 {
+					offset += 4 - olen%4
+				}
+			}
+		default:
+			return nil
+		}
+	}
+	return nil
+}
+
+func min2(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
--- a/backend/utils/mail/tnef_diag7_test.go
+++ b/backend/utils/mail/tnef_diag7_test.go
@@ -0,0 +1,273 @@
+package internal
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/teamwork/tnef"
+)
+
+func TestTNEFRecursiveExtract(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	f, _ := os.Open(testFile)
+	defer f.Close()
+
+	outerEmail, _ := Parse(f)
+	var innerData []byte
+	for _, att := range outerEmail.Attachments {
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			innerData, _ = io.ReadAll(att.Data)
+			break
+		}
+	}
+
+	innerEmail, _ := Parse(bytes.NewReader(innerData))
+	for _, att := range innerEmail.Attachments {
+		rawData, _ := io.ReadAll(att.Data)
+		if strings.ToLower(att.Filename) != "winmail.dat" {
+			continue
+		}
+
+		fmt.Println("=== Level 0 (top TNEF) ===")
+		atts, body := recursiveExtract(rawData, 0)
+		fmt.Printf("\nTotal extracted attachments: %d\n", len(atts))
+		for i, a := range atts {
+			fmt.Printf("  [%d] %q (%d bytes)\n", i, a.Title, len(a.Data))
+		}
+		fmt.Printf("Body HTML len: %d\n", len(body))
+		if len(body) > 0 && len(body) < 500 {
+			fmt.Printf("Body: %s\n", body)
+		}
+	}
+}
+
+func recursiveExtract(tnefData []byte, depth int) ([]*tnef.Attachment, string) {
+	prefix := strings.Repeat("  ", depth)
+
+	decoded, err := tnef.Decode(tnefData)
+	if err != nil {
+		fmt.Printf("%sDecode error: %v\n", prefix, err)
+		return nil, ""
+	}
+
+	// Collect body
+	bodyHTML := string(decoded.BodyHTML)
+	bodyText := string(decoded.Body)
+
+	// Check for RTF body in attributes
+	for _, attr := range decoded.Attributes {
+		if attr.Name == 0x1009 {
+			fmt.Printf("%sFound PR_RTF_COMPRESSED: %d bytes\n", prefix, len(attr.Data))
+		}
+		if attr.Name == 0x1000 {
+			fmt.Printf("%sFound PR_BODY: %d bytes\n", prefix, len(attr.Data))
+			if bodyText == "" {
+				bodyText = string(attr.Data)
+			}
+		}
+		if attr.Name == 0x1013 || attr.Name == 0x1035 {
+			fmt.Printf("%sFound PR_BODY_HTML/PR_HTML: %d bytes\n", prefix, len(attr.Data))
+			if bodyHTML == "" {
+				bodyHTML = string(attr.Data)
+			}
+		}
+	}
+
+	fmt.Printf("%sAttachments: %d, Body: %d, BodyHTML: %d\n",
+		prefix, len(decoded.Attachments), len(bodyText), len(bodyHTML))
+
+	var allAttachments []*tnef.Attachment
+
+	// Collect real attachments (skip placeholders)
+	for _, a := range decoded.Attachments {
+		if a.Title == "Untitled Attachment" && len(a.Data) < 200 {
+			fmt.Printf("%sSkipping placeholder: %q (%d bytes)\n", prefix, a.Title, len(a.Data))
+			continue
+		}
+		allAttachments = append(allAttachments, a)
+	}
+
+	// Now scan for embedded messages in raw TNEF
+	embeddedStreams := findEmbeddedTNEFStreams(tnefData)
+	for i, stream := range embeddedStreams {
+		fmt.Printf("%s--- Recursing into embedded message %d (%d bytes) ---\n", prefix, i, len(stream))
+		subAtts, subBody := recursiveExtract(stream, depth+1)
+		allAttachments = append(allAttachments, subAtts...)
+		if bodyHTML == "" && subBody != "" {
+			bodyHTML = subBody
+		}
+	}
+
+	if bodyHTML != "" {
+		return allAttachments, bodyHTML
+	}
+	return allAttachments, bodyText
+}
+
+func findEmbeddedTNEFStreams(tnefData []byte) [][]byte {
+	var streams [][]byte
+
+	// Navigate through TNEF attributes
+	offset := 6
+	for offset+9 < len(tnefData) {
+		level := tnefData[offset]
+		attrID := binary.LittleEndian.Uint32(tnefData[offset+1 : offset+5])
+		attrLen := int(binary.LittleEndian.Uint32(tnefData[offset+5 : offset+9]))
+		dataStart := offset + 9
+
+		if dataStart+attrLen > len(tnefData) {
+			break
+		}
+
+		// attAttachment (0x9005) at attachment level
+		if level == 0x02 && attrID == 0x00069005 && attrLen > 100 {
+			mapiData := tnefData[dataStart : dataStart+attrLen]
+			embedded := extractPRAttachDataObj2(mapiData)
+			if embedded != nil && len(embedded) > 22 {
+				// Skip 16-byte GUID, check for TNEF signature
+				afterGuid := embedded[16:]
+				if len(afterGuid) >= 4 {
+					sig := binary.LittleEndian.Uint32(afterGuid[0:4])
+					if sig == 0x223E9F78 {
+						streams = append(streams, afterGuid)
+					}
+				}
+			}
+		}
+
+		offset += 9 + attrLen + 2
+	}
+	return streams
+}
+
+func extractPRAttachDataObj2(mapiData []byte) []byte {
+	if len(mapiData) < 4 {
+		return nil
+	}
+	count := int(binary.LittleEndian.Uint32(mapiData[0:4]))
+	offset := 4
+
+	for i := 0; i < count && offset+4 <= len(mapiData); i++ {
+		propTag := binary.LittleEndian.Uint32(mapiData[offset : offset+4])
+		propType := propTag & 0xFFFF
+		propID := (propTag >> 16) & 0xFFFF
+		offset += 4
+
+		if propID >= 0x8000 {
+			if offset+20 > len(mapiData) {
+				return nil
+			}
+			kind := binary.LittleEndian.Uint32(mapiData[offset+16 : offset+20])
+			offset += 20
+			if kind == 0 {
+				offset += 4
+			} else {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				nameLen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4 + nameLen
+				if nameLen%4 != 0 {
+					offset += 4 - nameLen%4
+				}
+			}
+		}
+
+		switch propType {
+		case 0x0002:
+			offset += 4
+		case 0x0003:
+			offset += 4
+		case 0x000B:
+			offset += 4
+		case 0x0040:
+			offset += 8
+		case 0x001E, 0x001F:
+			if offset+4 > len(mapiData) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				slen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4 + slen
+				if slen%4 != 0 {
+					offset += 4 - slen%4
+				}
+			}
+		case 0x0102:
+			if offset+4 > len(mapiData) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				blen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4 + blen
+				if blen%4 != 0 {
+					offset += 4 - blen%4
+				}
+			}
+		case 0x000D:
+			if offset+4 > len(mapiData) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				olen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4
+				if propID == 0x3701 {
+					return mapiData[offset : offset+olen]
+				}
+				offset += olen
+				if olen%4 != 0 {
+					offset += 4 - olen%4
+				}
+			}
+		case 0x1003:
+			if offset+4 > len(mapiData) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+			offset += 4 + cnt*4
+		case 0x1102:
+			if offset+4 > len(mapiData) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+			offset += 4
+			for j := 0; j < cnt; j++ {
+				if offset+4 > len(mapiData) {
+					return nil
+				}
+				blen := int(binary.LittleEndian.Uint32(mapiData[offset : offset+4]))
+				offset += 4 + blen
+				if blen%4 != 0 {
+					offset += 4 - blen%4
+				}
+			}
+		default:
+			return nil
+		}
+	}
+	return nil
+}
--- a/backend/utils/mail/tnef_diag8_test.go
+++ b/backend/utils/mail/tnef_diag8_test.go
@@ -0,0 +1,97 @@
+package internal
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/teamwork/tnef"
+)
+
+func TestTNEFDeepAttachment(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	f, _ := os.Open(testFile)
+	defer f.Close()
+
+	outerEmail, _ := Parse(f)
+	var innerData []byte
+	for _, att := range outerEmail.Attachments {
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			innerData, _ = io.ReadAll(att.Data)
+			break
+		}
+	}
+
+	innerEmail, _ := Parse(bytes.NewReader(innerData))
+	for _, att := range innerEmail.Attachments {
+		rawData, _ := io.ReadAll(att.Data)
+		if strings.ToLower(att.Filename) != "winmail.dat" {
+			continue
+		}
+
+		// Dig to level 2: top → embedded[0] → embedded[0]
+		streams0 := findEmbeddedTNEFStreams(rawData)
+		if len(streams0) == 0 {
+			t.Fatal("no embedded streams at level 0")
+		}
+		streams1 := findEmbeddedTNEFStreams(streams0[0])
+		if len(streams1) == 0 {
+			t.Fatal("no embedded streams at level 1")
+		}
+
+		// Decode level 2
+		decoded2, err := tnef.Decode(streams1[0])
+		if err != nil {
+			t.Fatalf("level 2 decode: %v", err)
+		}
+
+		fmt.Printf("Level 2 attachments: %d\n", len(decoded2.Attachments))
+		for i, a := range decoded2.Attachments {
+			fmt.Printf("  [%d] title=%q size=%d\n", i, a.Title, len(a.Data))
+			if len(a.Data) > 20 {
+				fmt.Printf("      first 20 bytes: %x\n", a.Data[:20])
+				// Check for EML, MSG, TNEF signatures
+				if len(a.Data) >= 4 {
+					sig := binary.LittleEndian.Uint32(a.Data[0:4])
+					if sig == 0x223E9F78 {
+						fmt.Println("      -> TNEF stream!")
+					}
+				}
+				if len(a.Data) >= 8 && bytes.Equal(a.Data[:8], []byte{0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1}) {
+					fmt.Println("      -> MSG (OLE2) file!")
+				}
+				// Check if text/EML
+				if a.Data[0] < 128 && a.Data[0] >= 32 {
+					preview := string(a.Data[:min2(200, len(a.Data))])
+					if strings.Contains(preview, "From:") || strings.Contains(preview, "Content-Type") || strings.Contains(preview, "MIME") || strings.Contains(preview, "Received:") {
+						fmt.Printf("      -> Looks like an EML file! First 200 chars: %s\n", preview)
+					} else {
+						fmt.Printf("      -> Text data: %.200s\n", preview)
+					}
+				}
+			}
+		}
+
+		// Also check level 2's attAttachment for embedded msgs
+		streams2 := findEmbeddedTNEFStreams(streams1[0])
+		fmt.Printf("\nLevel 2 embedded TNEF streams: %d\n", len(streams2))
+
+		// Check all MAPI attributes at level 2
+		fmt.Println("\nLevel 2 MAPI attributes:")
+		for _, attr := range decoded2.Attributes {
+			fmt.Printf("  0x%04X: %d bytes\n", attr.Name, len(attr.Data))
+			// PR_BODY
+			if attr.Name == 0x1000 && len(attr.Data) < 500 {
+				fmt.Printf("    PR_BODY: %s\n", string(attr.Data))
+			}
+		}
+	}
+}
--- a/backend/utils/mail/tnef_diag_test.go
+++ b/backend/utils/mail/tnef_diag_test.go
@@ -0,0 +1,79 @@
+package internal
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/teamwork/tnef"
+)
+
+func TestTNEFDiag(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	f, _ := os.Open(testFile)
+	defer f.Close()
+
+	// Parse the PEC outer envelope
+	outerEmail, err := Parse(f)
+	if err != nil {
+		t.Fatalf("parse outer: %v", err)
+	}
+
+	// Find postacert.eml
+	var innerData []byte
+	for _, att := range outerEmail.Attachments {
+		if strings.Contains(strings.ToLower(att.Filename), "postacert.eml") {
+			innerData, _ = io.ReadAll(att.Data)
+			break
+		}
+	}
+	if innerData == nil {
+		t.Fatal("no postacert.eml found")
+	}
+
+	// Parse inner email
+	innerEmail, err := Parse(bytes.NewReader(innerData))
+	if err != nil {
+		t.Fatalf("parse inner: %v", err)
+	}
+
+	fmt.Printf("Inner attachments: %d\n", len(innerEmail.Attachments))
+	for i, att := range innerEmail.Attachments {
+		data, _ := io.ReadAll(att.Data)
+		fmt.Printf("  [%d] filename=%q contentType=%q size=%d\n", i, att.Filename, att.ContentType, len(data))
+
+		if strings.ToLower(att.Filename) == "winmail.dat" ||
+			strings.Contains(strings.ToLower(att.ContentType), "ms-tnef") {
+
+			fmt.Printf("  Found TNEF! First 20 bytes: %x\n", data[:min(20, len(data))])
+			fmt.Printf("  isTNEFData: %v\n", isTNEFData(data))
+
+			decoded, err := tnef.Decode(data)
+			if err != nil {
+				fmt.Printf("  TNEF decode error: %v\n", err)
+				continue
+			}
+			fmt.Printf("  TNEF Body len: %d\n", len(decoded.Body))
+			fmt.Printf("  TNEF BodyHTML len: %d\n", len(decoded.BodyHTML))
+			fmt.Printf("  TNEF Attachments: %d\n", len(decoded.Attachments))
+			for j, ta := range decoded.Attachments {
+				fmt.Printf("    [%d] title=%q size=%d\n", j, ta.Title, len(ta.Data))
+			}
+			fmt.Printf("  TNEF Attributes: %d\n", len(decoded.Attributes))
+		}
+	}
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
--- a/backend/utils/mail/tnef_reader.go
+++ b/backend/utils/mail/tnef_reader.go
@@ -0,0 +1,444 @@
+package internal
+
+import (
+	"encoding/binary"
+	"mime"
+	"path/filepath"
+	"strings"
+
+	"github.com/teamwork/tnef"
+)
+
+// tnefMagic is the TNEF file signature (little-endian 0x223E9F78).
+var tnefMagic = []byte{0x78, 0x9F, 0x3E, 0x22}
+
+const maxTNEFDepth = 10
+
+// isTNEFData returns true if the given byte slice starts with the TNEF magic number.
+func isTNEFData(data []byte) bool {
+	return len(data) >= 4 &&
+		data[0] == tnefMagic[0] &&
+		data[1] == tnefMagic[1] &&
+		data[2] == tnefMagic[2] &&
+		data[3] == tnefMagic[3]
+}
+
+// isTNEFAttachment returns true if an attachment is a TNEF-encoded winmail.dat.
+// Detection is based on filename, content-type, or the TNEF magic bytes.
+func isTNEFAttachment(att EmailAttachment) bool {
+	filenameLower := strings.ToLower(att.Filename)
+	if filenameLower == "winmail.dat" {
+		return true
+	}
+	ctLower := strings.ToLower(att.ContentType)
+	if strings.Contains(ctLower, "application/ms-tnef") ||
+		strings.Contains(ctLower, "application/vnd.ms-tnef") {
+		return true
+	}
+	return isTNEFData(att.Data)
+}
+
+// extractTNEFAttachments decodes a TNEF blob and returns the files embedded
+// inside it, recursively following nested embedded MAPI messages.
+func extractTNEFAttachments(data []byte) ([]EmailAttachment, error) {
+	return extractTNEFRecursive(data, 0)
+}
+
+func extractTNEFRecursive(data []byte, depth int) ([]EmailAttachment, error) {
+	if depth > maxTNEFDepth {
+		return nil, nil
+	}
+
+	decoded, err := tnef.Decode(data)
+	if err != nil {
+		return nil, err
+	}
+
+	var attachments []EmailAttachment
+
+	// Collect non-placeholder file attachments from the library output.
+	for _, att := range decoded.Attachments {
+		if len(att.Data) == 0 {
+			continue
+		}
+		// Skip the small MAPI placeholder text ("L'allegato è un messaggio
+		// incorporato MAPI 1.0...") that Outlook inserts for embedded messages.
+		if isEmbeddedMsgPlaceholder(att) {
+			continue
+		}
+
+		filename := att.Title
+		if filename == "" || filename == "Untitled Attachment" {
+			filename = inferFilename(att.Data)
+		}
+
+		attachments = append(attachments, EmailAttachment{
+			Filename:    filename,
+			ContentType: mimeTypeFromFilename(filename),
+			Data:        att.Data,
+		})
+	}
+
+	// Recursively dig into embedded MAPI messages stored in
+	// attAttachment (0x9005) → PR_ATTACH_DATA_OBJ (0x3701).
+	for _, stream := range findEmbeddedTNEFStreamsFromRaw(data) {
+		subAtts, _ := extractTNEFRecursive(stream, depth+1)
+		attachments = append(attachments, subAtts...)
+	}
+
+	return attachments, nil
+}
+
+// isEmbeddedMsgPlaceholder returns true if the attachment is a tiny placeholder
+// that Outlook generates for embedded MAPI messages ("L'allegato è un messaggio
+// incorporato MAPI 1.0" or equivalent in other languages).
+func isEmbeddedMsgPlaceholder(att *tnef.Attachment) bool {
+	if len(att.Data) > 300 {
+		return false
+	}
+	lower := strings.ToLower(string(att.Data))
+	return strings.Contains(lower, "mapi 1.0") ||
+		strings.Contains(lower, "embedded message") ||
+		strings.Contains(lower, "messaggio incorporato")
+}
+
+// inferFilename picks a reasonable filename based on the data's magic bytes.
+func inferFilename(data []byte) string {
+	if looksLikeEML(data) {
+		return "embedded_message.eml"
+	}
+	if isTNEFData(data) {
+		return "embedded.dat"
+	}
+	if len(data) >= 8 {
+		if data[0] == 0xD0 && data[1] == 0xCF && data[2] == 0x11 && data[3] == 0xE0 {
+			return "embedded_message.msg"
+		}
+	}
+	return "attachment.dat"
+}
+
+// looksLikeEML returns true if data starts with typical RFC 5322 headers.
+func looksLikeEML(data []byte) bool {
+	if len(data) < 20 {
+		return false
+	}
+	// Quick check: must start with printable ASCII
+	if data[0] < 32 || data[0] > 126 {
+		return false
+	}
+	prefix := strings.ToLower(string(data[:min(200, len(data))]))
+	return strings.HasPrefix(prefix, "mime-version:") ||
+		strings.HasPrefix(prefix, "from:") ||
+		strings.HasPrefix(prefix, "received:") ||
+		strings.HasPrefix(prefix, "date:") ||
+		strings.HasPrefix(prefix, "content-type:") ||
+		strings.HasPrefix(prefix, "return-path:")
+}
+
+// expandTNEFAttachments iterates over the attachment list and replaces any
+// TNEF-encoded winmail.dat entries with the files they contain. Attachments
+// that are not TNEF are passed through unchanged.
+func expandTNEFAttachments(attachments []EmailAttachment) []EmailAttachment {
+	var result []EmailAttachment
+	for _, att := range attachments {
+		if isTNEFAttachment(att) {
+			extracted, err := extractTNEFAttachments(att.Data)
+			if err == nil && len(extracted) > 0 {
+				result = append(result, extracted...)
+				continue
+			}
+			// If extraction fails, keep the original blob.
+		}
+		result = append(result, att)
+	}
+	return result
+}
+
+// ---------------------------------------------------------------------------
+// Raw TNEF attribute scanner — extracts nested TNEF streams from embedded
+// MAPI messages that the teamwork/tnef library does not handle.
+// ---------------------------------------------------------------------------
+
+// findEmbeddedTNEFStreamsFromRaw scans the raw TNEF byte stream for
+// attAttachment (0x00069005) attribute blocks, parses their MAPI properties,
+// and extracts any PR_ATTACH_DATA_OBJ (0x3701) values that begin with a
+// TNEF signature.
+func findEmbeddedTNEFStreamsFromRaw(tnefData []byte) [][]byte {
+	if len(tnefData) < 6 || !isTNEFData(tnefData) {
+		return nil
+	}
+
+	var streams [][]byte
+	offset := 6 // skip TNEF signature (4) + key (2)
+
+	for offset+9 < len(tnefData) {
+		level := tnefData[offset]
+		attrID := binary.LittleEndian.Uint32(tnefData[offset+1 : offset+5])
+		attrLen := int(binary.LittleEndian.Uint32(tnefData[offset+5 : offset+9]))
+		dataStart := offset + 9
+
+		if dataStart+attrLen > len(tnefData) || attrLen < 0 {
+			break
+		}
+
+		// attAttachment (0x00069005) at attachment level (0x02)
+		if level == 0x02 && attrID == 0x00069005 && attrLen > 100 {
+			mapiData := tnefData[dataStart : dataStart+attrLen]
+			embedded := extractPRAttachDataObjFromMAPI(mapiData)
+			if embedded != nil && len(embedded) > 22 {
+				// Skip the 16-byte IID_IMessage GUID
+				afterGuid := embedded[16:]
+				if isTNEFData(afterGuid) {
+					streams = append(streams, afterGuid)
+				}
+			}
+		}
+
+		// level(1) + id(4) + len(4) + data(attrLen) + checksum(2)
+		offset += 9 + attrLen + 2
+	}
+	return streams
+}
+
+// extractPRAttachDataObjFromMAPI parses a MAPI properties block (from an
+// attAttachment attribute) and returns the raw value of PR_ATTACH_DATA_OBJ
+// (property ID 0x3701, type PT_OBJECT 0x000D).
+func extractPRAttachDataObjFromMAPI(data []byte) []byte {
+	if len(data) < 4 {
+		return nil
+	}
+	count := int(binary.LittleEndian.Uint32(data[0:4]))
+	off := 4
+
+	for i := 0; i < count && off+4 <= len(data); i++ {
+		propTag := binary.LittleEndian.Uint32(data[off : off+4])
+		propType := propTag & 0xFFFF
+		propID := (propTag >> 16) & 0xFFFF
+		off += 4
+
+		// Named properties (ID >= 0x8000) have extra GUID + kind fields.
+		if propID >= 0x8000 {
+			if off+20 > len(data) {
+				return nil
+			}
+			kind := binary.LittleEndian.Uint32(data[off+16 : off+20])
+			off += 20
+			if kind == 0 { // MNID_ID
+				off += 4
+			} else { // MNID_STRING
+				if off+4 > len(data) {
+					return nil
+				}
+				nameLen := int(binary.LittleEndian.Uint32(data[off : off+4]))
+				off += 4 + nameLen
+				off += padTo4(nameLen)
+			}
+		}
+
+		off = skipMAPIPropValue(data, off, propType, propID)
+		if off < 0 {
+			return nil // parse error
+		}
+		// If skipMAPIPropValue returned a special sentinel, extract it.
+		// We use a hack: skipMAPIPropValue can't return the data directly,
+		// so we handle PT_OBJECT / 0x3701 inline below.
+	}
+
+	// Simpler approach: re-scan specifically for 0x3701.
+	return extractPRAttachDataObjDirect(data)
+}
+
+// extractPRAttachDataObjDirect re-scans the MAPI property block and
+// returns the raw value of PR_ATTACH_DATA_OBJ (0x3701, PT_OBJECT).
+func extractPRAttachDataObjDirect(data []byte) []byte {
+	if len(data) < 4 {
+		return nil
+	}
+	count := int(binary.LittleEndian.Uint32(data[0:4]))
+	off := 4
+
+	for i := 0; i < count && off+4 <= len(data); i++ {
+		propTag := binary.LittleEndian.Uint32(data[off : off+4])
+		propType := propTag & 0xFFFF
+		propID := (propTag >> 16) & 0xFFFF
+		off += 4
+
+		// Skip named property headers.
+		if propID >= 0x8000 {
+			if off+20 > len(data) {
+				return nil
+			}
+			kind := binary.LittleEndian.Uint32(data[off+16 : off+20])
+			off += 20
+			if kind == 0 {
+				off += 4
+			} else {
+				if off+4 > len(data) {
+					return nil
+				}
+				nameLen := int(binary.LittleEndian.Uint32(data[off : off+4]))
+				off += 4 + nameLen
+				off += padTo4(nameLen)
+			}
+		}
+
+		switch propType {
+		case 0x0002: // PT_SHORT (padded to 4)
+			off += 4
+		case 0x0003, 0x000A: // PT_LONG, PT_ERROR
+			off += 4
+		case 0x000B: // PT_BOOLEAN (padded to 4)
+			off += 4
+		case 0x0004: // PT_FLOAT
+			off += 4
+		case 0x0005: // PT_DOUBLE
+			off += 8
+		case 0x0006: // PT_CURRENCY
+			off += 8
+		case 0x0007: // PT_APPTIME
+			off += 8
+		case 0x0014: // PT_I8
+			off += 8
+		case 0x0040: // PT_SYSTIME
+			off += 8
+		case 0x0048: // PT_CLSID
+			off += 16
+		case 0x001E, 0x001F: // PT_STRING8, PT_UNICODE
+			off = skipCountedBlobs(data, off)
+		case 0x0102: // PT_BINARY
+			off = skipCountedBlobs(data, off)
+		case 0x000D: // PT_OBJECT
+			if off+4 > len(data) {
+				return nil
+			}
+			cnt := int(binary.LittleEndian.Uint32(data[off : off+4]))
+			off += 4
+			for j := 0; j < cnt; j++ {
+				if off+4 > len(data) {
+					return nil
+				}
+				olen := int(binary.LittleEndian.Uint32(data[off : off+4]))
+				off += 4
+				if propID == 0x3701 && off+olen <= len(data) {
+					return data[off : off+olen]
+				}
+				off += olen
+				off += padTo4(olen)
+			}
+		case 0x1002: // PT_MV_SHORT
+			off = skipMVFixed(data, off, 4)
+		case 0x1003: // PT_MV_LONG
+			off = skipMVFixed(data, off, 4)
+		case 0x1005: // PT_MV_DOUBLE
+			off = skipMVFixed(data, off, 8)
+		case 0x1014: // PT_MV_I8
+			off = skipMVFixed(data, off, 8)
+		case 0x1040: // PT_MV_SYSTIME
+			off = skipMVFixed(data, off, 8)
+		case 0x101E, 0x101F: // PT_MV_STRING8, PT_MV_UNICODE
+			off = skipCountedBlobs(data, off)
+		case 0x1048: // PT_MV_CLSID
+			off = skipMVFixed(data, off, 16)
+		case 0x1102: // PT_MV_BINARY
+			off = skipCountedBlobs(data, off)
+		default:
+			// Unknown type, can't continue
+			return nil
+		}
+
+		if off < 0 || off > len(data) {
+			return nil
+		}
+	}
+	return nil
+}
+
+// skipCountedBlobs advances past a MAPI value that stores count + N
+// length-prefixed blobs (used by PT_STRING8, PT_UNICODE, PT_BINARY, and
+// their multi-valued variants).
+func skipCountedBlobs(data []byte, off int) int {
+	if off+4 > len(data) {
+		return -1
+	}
+	cnt := int(binary.LittleEndian.Uint32(data[off : off+4]))
+	off += 4
+	for j := 0; j < cnt; j++ {
+		if off+4 > len(data) {
+			return -1
+		}
+		blen := int(binary.LittleEndian.Uint32(data[off : off+4]))
+		off += 4 + blen
+		off += padTo4(blen)
+	}
+	return off
+}
+
+// skipMVFixed advances past a multi-valued fixed-size property
+// (count followed by count*elemSize bytes).
+func skipMVFixed(data []byte, off int, elemSize int) int {
+	if off+4 > len(data) {
+		return -1
+	}
+	cnt := int(binary.LittleEndian.Uint32(data[off : off+4]))
+	off += 4 + cnt*elemSize
+	return off
+}
+
+// skipMAPIPropValue is a generic value skipper (unused in the current flow
+// but kept for completeness).
+func skipMAPIPropValue(data []byte, off int, propType uint32, _ uint32) int {
+	switch propType {
+	case 0x0002:
+		return off + 4
+	case 0x0003, 0x000A, 0x000B, 0x0004:
+		return off + 4
+	case 0x0005, 0x0006, 0x0007, 0x0014, 0x0040:
+		return off + 8
+	case 0x0048:
+		return off + 16
+	case 0x001E, 0x001F, 0x0102, 0x000D:
+		return skipCountedBlobs(data, off)
+	case 0x1002, 0x1003:
+		return skipMVFixed(data, off, 4)
+	case 0x1005, 0x1014, 0x1040:
+		return skipMVFixed(data, off, 8)
+	case 0x1048:
+		return skipMVFixed(data, off, 16)
+	case 0x101E, 0x101F, 0x1102:
+		return skipCountedBlobs(data, off)
+	default:
+		return -1
+	}
+}
+
+// padTo4 returns the number of padding bytes needed to reach a 4-byte boundary.
+func padTo4(n int) int {
+	r := n % 4
+	if r == 0 {
+		return 0
+	}
+	return 4 - r
+}
+
+// ---------------------------------------------------------------------------
+// MIME type helper
+// ---------------------------------------------------------------------------
+
+// mimeTypeFromFilename guesses the MIME type from a file extension.
+// Falls back to "application/octet-stream" when the type is unknown.
+func mimeTypeFromFilename(filename string) string {
+	ext := strings.ToLower(filepath.Ext(filename))
+	if ext == "" {
+		return "application/octet-stream"
+	}
+	t := mime.TypeByExtension(ext)
+	if t == "" {
+		return "application/octet-stream"
+	}
+	// Strip any parameters (e.g. "; charset=utf-8")
+	if idx := strings.Index(t, ";"); idx != -1 {
+		t = strings.TrimSpace(t[:idx])
+	}
+	return t
+}
--- a/backend/utils/mail/tnef_reader_test.go
+++ b/backend/utils/mail/tnef_reader_test.go
@@ -0,0 +1,59 @@
+package internal
+
+import (
+	"fmt"
+	"os"
+	"testing"
+)
+
+func TestReadEmlWithTNEF(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	// First try the PEC reader (this is a PEC email)
+	email, err := ReadPecInnerEml(testFile)
+	if err != nil {
+		t.Fatalf("ReadPecInnerEml failed: %v", err)
+	}
+
+	fmt.Printf("Subject: %s\n", email.Subject)
+	fmt.Printf("From: %s\n", email.From)
+	fmt.Printf("Attachment count: %d\n", len(email.Attachments))
+
+	hasWinmailDat := false
+	for i, att := range email.Attachments {
+		fmt.Printf("  [%d] %s (%s, %d bytes)\n", i, att.Filename, att.ContentType, len(att.Data))
+		if att.Filename == "winmail.dat" {
+			hasWinmailDat = true
+		}
+	}
+
+	if hasWinmailDat {
+		t.Error("winmail.dat should have been expanded into its contained attachments")
+	}
+
+	if len(email.Attachments) == 0 {
+		t.Error("expected at least one attachment after TNEF expansion")
+	}
+}
+
+func TestReadEmlFallback(t *testing.T) {
+	testFile := `H:\Dev\Gits\EMLy\EML_TNEF.eml`
+	if _, err := os.Stat(testFile); os.IsNotExist(err) {
+		t.Skip("test EML file not present")
+	}
+
+	// Also verify the plain EML reader path
+	email, err := ReadEmlFile(testFile)
+	if err != nil {
+		t.Fatalf("ReadEmlFile failed: %v", err)
+	}
+
+	fmt.Printf("[EML] Subject: %s\n", email.Subject)
+	fmt.Printf("[EML] Attachment count: %d\n", len(email.Attachments))
+	for i, att := range email.Attachments {
+		fmt.Printf("  [%d] %s (%s, %d bytes)\n", i, att.Filename, att.ContentType, len(att.Data))
+	}
+}
--- a/frontend/bun.lock
+++ b/frontend/bun.lock
@@ -5,7 +5,10 @@
    "": {
      "name": "frontend",
      "dependencies": {
+        "@rollup/rollup-win32-arm64-msvc": "^4.57.1",
+        "@types/html2canvas": "^1.0.0",
        "dompurify": "^3.3.1",
+        "html2canvas": "^1.4.1",
        "pdfjs-dist": "^5.4.624",
        "svelte-flags": "^3.0.1",
        "svelte-sonner": "^1.0.7",
@@ -187,7 +190,7 @@

    "@rollup/rollup-openharmony-arm64": ["@rollup/rollup-openharmony-arm64@4.55.1", "", { "os": "none", "cpu": "arm64" }, "sha512-xzm44KgEP11te3S2HCSyYf5zIzWmx3n8HDCc7EE59+lTcswEWNpvMLfd9uJvVX8LCg9QWG67Xt75AuHn4vgsXw=="],

-    "@rollup/rollup-win32-arm64-msvc": ["@rollup/rollup-win32-arm64-msvc@4.55.1", "", { "os": "win32", "cpu": "arm64" }, "sha512-yR6Bl3tMC/gBok5cz/Qi0xYnVbIxGx5Fcf/ca0eB6/6JwOY+SRUcJfI0OpeTpPls7f194as62thCt/2BjxYN8g=="],
+    "@rollup/rollup-win32-arm64-msvc": ["@rollup/rollup-win32-arm64-msvc@4.57.1", "", { "os": "win32", "cpu": "arm64" }, "sha512-O54mtsV/6LW3P8qdTcamQmuC990HDfR71lo44oZMZlXU4tzLrbvTii87Ni9opq60ds0YzuAlEr/GNwuNluZyMQ=="],

    "@rollup/rollup-win32-ia32-msvc": ["@rollup/rollup-win32-ia32-msvc@4.55.1", "", { "os": "win32", "cpu": "ia32" }, "sha512-3fZBidchE0eY0oFZBnekYCfg+5wAB0mbpCBuofh5mZuzIU/4jIVkbESmd2dOsFNS78b53CYv3OAtwqkZZmU5nA=="],

@@ -249,6 +252,8 @@

    "@types/estree": ["@types/estree@1.0.8", "", {}, "sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w=="],

+    "@types/html2canvas": ["@types/html2canvas@1.0.0", "", { "dependencies": { "html2canvas": "*" } }, "sha512-BJpVf+FIN9UERmzhbtUgpXj6XBZpG67FMgBLLoj9HZKd9XifcCpSV+UnFcwTZfEyun4U/KmCrrVOG7829L589w=="],
+
    "@types/node": ["@types/node@24.10.6", "", { "dependencies": { "undici-types": "~7.16.0" } }, "sha512-B8h60xgJMR/xmgyX9fncRzEW9gCxoJjdenUhke2v1JGOd/V66KopmWrLPXi5oUI4VuiGK+d+HlXJjDRZMj21EQ=="],

    "@types/trusted-types": ["@types/trusted-types@2.0.7", "", {}, "sha512-ScaPdn1dQczgbl0QFTeTOmVHFULt394XJgOQNoyVhZ6r2vLnMLJfBPd53SB52T/3G36VI1/g2MZaX0cwDuXsfw=="],
@@ -261,6 +266,8 @@

    "axobject-query": ["axobject-query@4.1.0", "", {}, "sha512-qIj0G9wZbMGNLjLmg1PT6v2mE9AH2zlnADJD/2tC6E00hgmhUOfEB6greHPAfLRSufHqROIUTkw6E+M3lH0PTQ=="],

+    "base64-arraybuffer": ["base64-arraybuffer@1.0.2", "", {}, "sha512-I3yl4r9QB5ZRY3XuJVEPfc2XhZO6YweFPI+UovAzn+8/hb3oJ6lnysaFcjVpkCPfVWFUDvoZ8kmVDP7WyRtYtQ=="],
+
    "bits-ui": ["bits-ui@2.15.4", "", { "dependencies": { "@floating-ui/core": "^1.7.1", "@floating-ui/dom": "^1.7.1", "esm-env": "^1.1.2", "runed": "^0.35.1", "svelte-toolbelt": "^0.10.6", "tabbable": "^6.2.0" }, "peerDependencies": { "@internationalized/date": "^3.8.1", "svelte": "^5.33.0" } }, "sha512-7H9YUfp03KOk1LVDh8wPYSRPxlZgG/GRWLNSA8QC73/8Z8ytun+DWJhIuibyFyz7A0cP/RANVcB4iDrbY8q+Og=="],

    "chokidar": ["chokidar@4.0.3", "", { "dependencies": { "readdirp": "^4.0.1" } }, "sha512-Qgzu8kfBvo+cA4962jnP1KkS6Dop5NS6g7R5LFYJr4b8Ub94PPQXUksCw9PvXoeXPRRddRNC5C1JQUR2SMGtnA=="],
@@ -277,6 +284,8 @@

    "core-util-is": ["core-util-is@1.0.3", "", {}, "sha512-ZQBvi1DcpJ4GDqanjucZ2Hj3wEO5pZDS89BWbkcrvdxksJorwUDDZamX9ldFkp9aw2lmBDLgkObEA4DWNJ9FYQ=="],

+    "css-line-break": ["css-line-break@2.1.0", "", { "dependencies": { "utrie": "^1.0.2" } }, "sha512-FHcKFCZcAha3LwfVBhCQbW2nCNbkZXn7KVUJcsT5/P8YmfsVja0FMPJr0B903j/E69HUphKiV9iQArX8SDYA4w=="],
+
    "cssesc": ["cssesc@3.0.0", "", { "bin": { "cssesc": "bin/cssesc" } }, "sha512-/Tb/JcjK111nNScGob5MNtsntNM1aCNUDipB/TkwZFhyDrrE47SOx/18wF2bbjgc3ZzCSKW1T5nt5EbFoAz/Vg=="],

    "dedent": ["dedent@1.5.1", "", { "peerDependencies": { "babel-plugin-macros": "^3.1.0" }, "optionalPeers": ["babel-plugin-macros"] }, "sha512-+LxW+KLWxu3HW3M2w2ympwtqPrqYRzU8fqi6Fhd18fBALe15blJPI/I4+UHveMVG6lJqB4JNd4UG0S5cnVHwIg=="],
@@ -307,6 +316,8 @@

    "graceful-fs": ["graceful-fs@4.2.11", "", {}, "sha512-RbJ5/jmFcNNCcDV5o9eTnBLJ/HszWV0P73bc+Ff4nS/rJj+YaS6IGyiOL0VoBYX+l1Wrl3k63h/KrH+nhJ0XvQ=="],

+    "html2canvas": ["html2canvas@1.4.1", "", { "dependencies": { "css-line-break": "^2.1.0", "text-segmentation": "^1.0.3" } }, "sha512-fPU6BHNpsyIhr8yyMpTLLxAbkaK8ArIBcmZIRiBLiDhjeqvXolaEmDGmELFuX9I4xDcaKKcJl+TKZLqruBbmWA=="],
+
    "human-id": ["human-id@4.1.3", "", { "bin": { "human-id": "dist/cli.js" } }, "sha512-tsYlhAYpjCKa//8rXZ9DqKEawhPoSytweBC2eNvcaDK+57RZLHGqNs3PZTQO6yekLFSuvA6AlnAfrw1uBvtb+Q=="],

    "inline-style-parser": ["inline-style-parser@0.2.7", "", {}, "sha512-Nb2ctOyNR8DqQoR0OwRG95uNWIC0C1lCgf5Naz5H6Ji72KZ8OcFZLz2P5sNgwlyoJ8Yif11oMuYs5pBQa86csA=="],
@@ -415,6 +426,8 @@

    "tapable": ["tapable@2.3.0", "", {}, "sha512-g9ljZiwki/LfxmQADO3dEY1CbpmXT5Hm2fJ+QaGKwSXUylMybePR7/67YW7jOrrvjEgL1Fmz5kzyAjWVWLlucg=="],

+    "text-segmentation": ["text-segmentation@1.0.3", "", { "dependencies": { "utrie": "^1.0.2" } }, "sha512-iOiPUo/BGnZ6+54OsWxZidGCsdU8YbE4PSpdPinp7DeMtUJNJBoJ/ouUSTJjHkh1KntHaltHl/gDs2FC4i5+Nw=="],
+
    "tinyglobby": ["tinyglobby@0.2.15", "", { "dependencies": { "fdir": "^6.5.0", "picomatch": "^4.0.3" } }, "sha512-j2Zq4NyQYG5XMST4cbs02Ak8iJUdxRM0XI5QyxXuZOzKOINmWurp3smXu3y5wDcJrptwpSjgXHzIQxR0omXljQ=="],

    "totalist": ["totalist@3.0.1", "", {}, "sha512-sf4i37nQ2LBx4m3wB74y+ubopq6W/dIzXg0FDGjsYnZHVa1Da8FH853wlL2gtUhg+xJXjfk3kUZS3BRoQeoQBQ=="],
@@ -433,6 +446,8 @@

    "util-deprecate": ["util-deprecate@1.0.2", "", {}, "sha512-EPD5q1uXyFxJpCrLnCc1nHnq3gOa6DZBocAIiI2TaSCA7VCJ1UJDMagCzIkXNsUYfD1daK//LTEQ8xiIbrHtcw=="],

+    "utrie": ["utrie@1.0.2", "", { "dependencies": { "base64-arraybuffer": "^1.0.2" } }, "sha512-1MLa5ouZiOmQzUbjbu9VmjLzn1QLXBhwpUa7kdLUQK+KQ5KA9I1vk5U4YHe/X2Ch7PYnJfWuWT+VbuxbGwljhw=="],
+
    "uuid": ["uuid@11.1.0", "", { "bin": { "uuid": "dist/esm/bin/uuid" } }, "sha512-0/A9rDy9P7cJ+8w1c9WD9V//9Wj15Ce2MPz8Ri6032usz+NfePxx5AcN3bN+r6ZL6jEo066/yNYB3tn4pQEx+A=="],

    "vite": ["vite@7.3.1", "", { "dependencies": { "esbuild": "^0.27.0", "fdir": "^6.5.0", "picomatch": "^4.0.3", "postcss": "^8.5.6", "rollup": "^4.43.0", "tinyglobby": "^0.2.15" }, "optionalDependencies": { "fsevents": "~2.3.3" }, "peerDependencies": { "@types/node": "^20.19.0 || >=22.12.0", "jiti": ">=1.21.0", "less": "^4.0.0", "lightningcss": "^1.21.0", "sass": "^1.70.0", "sass-embedded": "^1.70.0", "stylus": ">=0.54.8", "sugarss": "^5.0.0", "terser": "^5.16.0", "tsx": "^4.8.1", "yaml": "^2.4.2" }, "optionalPeers": ["@types/node", "jiti", "less", "lightningcss", "sass", "sass-embedded", "stylus", "sugarss", "terser", "tsx", "yaml"], "bin": { "vite": "bin/vite.js" } }, "sha512-w+N7Hifpc3gRjZ63vYBXA56dvvRlNWRczTdmCBBa+CotUzAPf5b7YMdMR/8CQoeYE5LX3W4wj6RYTgonm1b9DA=="],
@@ -469,6 +484,8 @@

    "paneforge/svelte-toolbelt": ["svelte-toolbelt@0.9.3", "", { "dependencies": { "clsx": "^2.1.1", "runed": "^0.29.0", "style-to-object": "^1.0.8" }, "peerDependencies": { "svelte": "^5.30.2" } }, "sha512-HCSWxCtVmv+c6g1ACb8LTwHVbDqLKJvHpo6J8TaqwUme2hj9ATJCpjCPNISR1OCq2Q4U1KT41if9ON0isINQZw=="],

+    "rollup/@rollup/rollup-win32-arm64-msvc": ["@rollup/rollup-win32-arm64-msvc@4.55.1", "", { "os": "win32", "cpu": "arm64" }, "sha512-yR6Bl3tMC/gBok5cz/Qi0xYnVbIxGx5Fcf/ca0eB6/6JwOY+SRUcJfI0OpeTpPls7f194as62thCt/2BjxYN8g=="],
+
    "svelte-sonner/runed": ["runed@0.28.0", "", { "dependencies": { "esm-env": "^1.0.0" }, "peerDependencies": { "svelte": "^5.7.0" } }, "sha512-k2xx7RuO9hWcdd9f+8JoBeqWtYrm5CALfgpkg2YDB80ds/QE4w0qqu34A7fqiAwiBBSBQOid7TLxwxVC27ymWQ=="],

    "mode-watcher/svelte-toolbelt/runed": ["runed@0.23.4", "", { "dependencies": { "esm-env": "^1.0.0" }, "peerDependencies": { "svelte": "^5.7.0" } }, "sha512-9q8oUiBYeXIDLWNK5DfCWlkL0EW3oGbk845VdKlPeia28l751VpfesaB/+7pI6rnbx1I6rqoZ2fZxptOJLxILA=="],
--- a/frontend/package.json.md5
+++ b/frontend/package.json.md5
@@ -1 +1 @@
-3c4a64d0cfb34e86fac16fceae842e43
+1697d40a08e09716b8c29ddebeabd1ad
--- a/frontend/src/lib/utils/mail/email-loader.ts
+++ b/frontend/src/lib/utils/mail/email-loader.ts
@@ -6,6 +6,8 @@ import {
  ReadEML,
  ReadMSG,
  ReadPEC,
+  ReadAuto,
+  DetectEmailFormat,
  ShowOpenFileDialog,
  SetCurrentMailFilePath,
  ConvertToUTF8,
@@ -23,7 +25,8 @@ export interface LoadEmailResult {
 }

 /**
- * Determines the email file type from the path
+ * Determines the email file type from the path extension (best-effort hint).
+ * Use DetectEmailFormat (backend) for reliable format detection.
 */
 export function getEmailFileType(filePath: string): 'eml' | 'msg' | null {
  const lowerPath = filePath.toLowerCase();
@@ -33,18 +36,57 @@ export function getEmailFileType(filePath: string): 'eml' | 'msg' | null {
 }

 /**
- * Checks if a file path is a valid email file
+ * Checks if a file path looks like an email file by extension.
+ * Returns true also for unknown extensions so the backend can attempt parsing.
 */
 export function isEmailFile(filePath: string): boolean {
-  return getEmailFileType(filePath) !== null;
+  return filePath.trim().length > 0;
 }

 /**
- * Loads an email from a file path
+ * Loads an email from a file path.
+ * Uses ReadAuto so the backend detects the format from the file's binary
+ * content, regardless of extension. Falls back to the legacy per-format
+ * readers only when the caller explicitly requests them.
+ *
 * @param filePath - Path to the email file
 * @returns LoadEmailResult with the email data or error
 */
 export async function loadEmailFromPath(filePath: string): Promise<LoadEmailResult> {
+  if (!filePath?.trim()) {
+    return { success: false, error: 'No file path provided.' };
+  }
+
+  try {
+    // ReadAuto detects the format (EML/PEC/MSG) by magic bytes and dispatches
+    // to the appropriate reader. This works for any extension, including
+    // unconventional ones like winmail.dat or no extension at all.
+    const email = await ReadAuto(filePath);
+
+    // Process body if needed (decode base64)
+    if (email?.body) {
+      const trimmed = email.body.trim();
+      if (looksLikeBase64(trimmed)) {
+        const decoded = tryDecodeBase64(trimmed);
+        if (decoded) {
+          email.body = decoded;
+        }
+      }
+    }
+
+    return { success: true, email, filePath };
+  } catch (error: unknown) {
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    console.error('Failed to load email:', error);
+    return { success: false, error: errorMessage };
+  }
+}
+
+/**
+ * Loads an email using the explicit per-format readers (legacy path).
+ * Prefer loadEmailFromPath for new code.
+ */
+export async function loadEmailFromPathLegacy(filePath: string): Promise<LoadEmailResult> {
  const fileType = getEmailFileType(filePath);

  if (!fileType) {
@@ -60,7 +102,6 @@ export async function loadEmailFromPath(filePath: string): Promise<LoadEmailResu
    if (fileType === 'msg') {
      email = await ReadMSG(filePath, true);
    } else {
-      // Try PEC first, fall back to regular EML
      try {
        email = await ReadPEC(filePath);
      } catch {
@@ -68,7 +109,6 @@ export async function loadEmailFromPath(filePath: string): Promise<LoadEmailResu
      }
    }

-    // Process body if needed (decode base64)
    if (email?.body) {
      const trimmed = email.body.trim();
      if (looksLikeBase64(trimmed)) {
@@ -79,18 +119,11 @@ export async function loadEmailFromPath(filePath: string): Promise<LoadEmailResu
      }
    }

-    return {
-      success: true,
-      email,
-      filePath,
-    };
+    return { success: true, email, filePath };
  } catch (error: unknown) {
    const errorMessage = error instanceof Error ? error.message : String(error);
    console.error('Failed to load email:', error);
-    return {
-      success: false,
-      error: errorMessage,
-    };
+    return { success: false, error: errorMessage };
  }
 }

--- a/frontend/src/lib/utils/mail/index.ts
+++ b/frontend/src/lib/utils/mail/index.ts
@@ -33,6 +33,7 @@ export {
  getEmailFileType,
  isEmailFile,
  loadEmailFromPath,
+  loadEmailFromPathLegacy,
  openAndLoadEmail,
  processEmailBody,
  type LoadEmailResult,
--- a/frontend/src/lib/wailsjs/go/main/App.d.ts
+++ b/frontend/src/lib/wailsjs/go/main/App.d.ts
@@ -1,15 +1,29 @@
 // Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
 // This file is automatically generated. DO NOT EDIT
-import {utils} from '../models';
 import {main} from '../models';
+import {utils} from '../models';
 import {internal} from '../models';

+export function CheckForUpdates():Promise<main.UpdateStatus>;
+
 export function CheckIsDefaultEMLHandler():Promise<boolean>;

+export function ConvertToUTF8(arg1:string):Promise<string>;
+
+export function CreateBugReportFolder():Promise<main.BugReportResult>;
+
+export function DetectEmailFormat(arg1:string):Promise<string>;
+
+export function DownloadUpdate():Promise<string>;
+
+export function ExportSettings(arg1:string):Promise<string>;
+
 export function FrontendLog(arg1:string,arg2:string):Promise<void>;

 export function GetConfig():Promise<utils.Config>;

+export function GetCurrentMailFilePath():Promise<string>;
+
 export function GetImageViewerData():Promise<main.ImageViewerData>;

 export function GetMachineData():Promise<utils.MachineInfo>;
@@ -18,14 +32,26 @@ export function GetPDFViewerData():Promise<main.PDFViewerData>;

 export function GetStartupFile():Promise<string>;

+export function GetUpdateStatus():Promise<main.UpdateStatus>;
+
 export function GetViewerData():Promise<main.ViewerData>;

+export function ImportSettings():Promise<string>;
+
+export function InstallUpdate(arg1:boolean):Promise<void>;
+
+export function InstallUpdateSilent():Promise<void>;
+
+export function InstallUpdateSilentFromPath(arg1:string):Promise<void>;
+
 export function IsDebuggerRunning():Promise<boolean>;

 export function OpenDefaultAppsSettings():Promise<void>;

 export function OpenEMLWindow(arg1:string,arg2:string):Promise<void>;

+export function OpenFolderInExplorer(arg1:string):Promise<void>;
+
 export function OpenImage(arg1:string,arg2:string):Promise<void>;

 export function OpenImageWindow(arg1:string,arg2:string):Promise<void>;
@@ -34,8 +60,12 @@ export function OpenPDF(arg1:string,arg2:string):Promise<void>;

 export function OpenPDFWindow(arg1:string,arg2:string):Promise<void>;

+export function OpenURLInBrowser(arg1:string):Promise<void>;
+
 export function QuitApp():Promise<void>;

+export function ReadAuto(arg1:string):Promise<internal.EmailData>;
+
 export function ReadEML(arg1:string):Promise<internal.EmailData>;

 export function ReadMSG(arg1:string,arg2:boolean):Promise<internal.EmailData>;
@@ -46,4 +76,16 @@ export function ReadPEC(arg1:string):Promise<internal.EmailData>;

 export function SaveConfig(arg1:utils.Config):Promise<void>;

+export function SaveScreenshot():Promise<string>;
+
+export function SaveScreenshotAs():Promise<string>;
+
+export function SetCurrentMailFilePath(arg1:string):Promise<void>;
+
+export function SetUpdateCheckerEnabled(arg1:boolean):Promise<void>;
+
 export function ShowOpenFileDialog():Promise<string>;
+
+export function SubmitBugReport(arg1:main.BugReportInput):Promise<main.SubmitBugReportResult>;
+
+export function TakeScreenshot():Promise<main.ScreenshotResult>;
--- a/frontend/src/lib/wailsjs/go/main/App.js
+++ b/frontend/src/lib/wailsjs/go/main/App.js
@@ -2,10 +2,34 @@
 // Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
 // This file is automatically generated. DO NOT EDIT

+export function CheckForUpdates() {
+  return window['go']['main']['App']['CheckForUpdates']();
+}
+
 export function CheckIsDefaultEMLHandler() {
  return window['go']['main']['App']['CheckIsDefaultEMLHandler']();
 }

+export function ConvertToUTF8(arg1) {
+  return window['go']['main']['App']['ConvertToUTF8'](arg1);
+}
+
+export function CreateBugReportFolder() {
+  return window['go']['main']['App']['CreateBugReportFolder']();
+}
+
+export function DetectEmailFormat(arg1) {
+  return window['go']['main']['App']['DetectEmailFormat'](arg1);
+}
+
+export function DownloadUpdate() {
+  return window['go']['main']['App']['DownloadUpdate']();
+}
+
+export function ExportSettings(arg1) {
+  return window['go']['main']['App']['ExportSettings'](arg1);
+}
+
 export function FrontendLog(arg1, arg2) {
  return window['go']['main']['App']['FrontendLog'](arg1, arg2);
 }
@@ -14,6 +38,10 @@ export function GetConfig() {
  return window['go']['main']['App']['GetConfig']();
 }

+export function GetCurrentMailFilePath() {
+  return window['go']['main']['App']['GetCurrentMailFilePath']();
+}
+
 export function GetImageViewerData() {
  return window['go']['main']['App']['GetImageViewerData']();
 }
@@ -30,10 +58,30 @@ export function GetStartupFile() {
  return window['go']['main']['App']['GetStartupFile']();
 }

+export function GetUpdateStatus() {
+  return window['go']['main']['App']['GetUpdateStatus']();
+}
+
 export function GetViewerData() {
  return window['go']['main']['App']['GetViewerData']();
 }

+export function ImportSettings() {
+  return window['go']['main']['App']['ImportSettings']();
+}
+
+export function InstallUpdate(arg1) {
+  return window['go']['main']['App']['InstallUpdate'](arg1);
+}
+
+export function InstallUpdateSilent() {
+  return window['go']['main']['App']['InstallUpdateSilent']();
+}
+
+export function InstallUpdateSilentFromPath(arg1) {
+  return window['go']['main']['App']['InstallUpdateSilentFromPath'](arg1);
+}
+
 export function IsDebuggerRunning() {
  return window['go']['main']['App']['IsDebuggerRunning']();
 }
@@ -46,6 +94,10 @@ export function OpenEMLWindow(arg1, arg2) {
  return window['go']['main']['App']['OpenEMLWindow'](arg1, arg2);
 }

+export function OpenFolderInExplorer(arg1) {
+  return window['go']['main']['App']['OpenFolderInExplorer'](arg1);
+}
+
 export function OpenImage(arg1, arg2) {
  return window['go']['main']['App']['OpenImage'](arg1, arg2);
 }
@@ -62,10 +114,18 @@ export function OpenPDFWindow(arg1, arg2) {
  return window['go']['main']['App']['OpenPDFWindow'](arg1, arg2);
 }

+export function OpenURLInBrowser(arg1) {
+  return window['go']['main']['App']['OpenURLInBrowser'](arg1);
+}
+
 export function QuitApp() {
  return window['go']['main']['App']['QuitApp']();
 }

+export function ReadAuto(arg1) {
+  return window['go']['main']['App']['ReadAuto'](arg1);
+}
+
 export function ReadEML(arg1) {
  return window['go']['main']['App']['ReadEML'](arg1);
 }
@@ -86,6 +146,30 @@ export function SaveConfig(arg1) {
  return window['go']['main']['App']['SaveConfig'](arg1);
 }

+export function SaveScreenshot() {
+  return window['go']['main']['App']['SaveScreenshot']();
+}
+
+export function SaveScreenshotAs() {
+  return window['go']['main']['App']['SaveScreenshotAs']();
+}
+
+export function SetCurrentMailFilePath(arg1) {
+  return window['go']['main']['App']['SetCurrentMailFilePath'](arg1);
+}
+
+export function SetUpdateCheckerEnabled(arg1) {
+  return window['go']['main']['App']['SetUpdateCheckerEnabled'](arg1);
+}
+
 export function ShowOpenFileDialog() {
  return window['go']['main']['App']['ShowOpenFileDialog']();
 }
+
+export function SubmitBugReport(arg1) {
+  return window['go']['main']['App']['SubmitBugReport'](arg1);
+}
+
+export function TakeScreenshot() {
+  return window['go']['main']['App']['TakeScreenshot']();
+}
--- a/frontend/src/lib/wailsjs/go/models.ts
+++ b/frontend/src/lib/wailsjs/go/models.ts
@@ -242,6 +242,44 @@ export namespace internal {

 export namespace main {
 	
+	export class BugReportInput {
+	    name: string;
+	    email: string;
+	    description: string;
+	    screenshotData: string;
+	    localStorageData: string;
+	    configData: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new BugReportInput(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.name = source["name"];
+	        this.email = source["email"];
+	        this.description = source["description"];
+	        this.screenshotData = source["screenshotData"];
+	        this.localStorageData = source["localStorageData"];
+	        this.configData = source["configData"];
+	    }
+	}
+	export class BugReportResult {
+	    folderPath: string;
+	    screenshotPath: string;
+	    mailFilePath: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new BugReportResult(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.folderPath = source["folderPath"];
+	        this.screenshotPath = source["screenshotPath"];
+	        this.mailFilePath = source["mailFilePath"];
+	    }
+	}
 	export class ImageViewerData {
 	    data: string;
 	    filename: string;
@@ -270,6 +308,70 @@ export namespace main {
 	        this.filename = source["filename"];
 	    }
 	}
+	export class ScreenshotResult {
+	    data: string;
+	    width: number;
+	    height: number;
+	    filename: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new ScreenshotResult(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.data = source["data"];
+	        this.width = source["width"];
+	        this.height = source["height"];
+	        this.filename = source["filename"];
+	    }
+	}
+	export class SubmitBugReportResult {
+	    zipPath: string;
+	    folderPath: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new SubmitBugReportResult(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.zipPath = source["zipPath"];
+	        this.folderPath = source["folderPath"];
+	    }
+	}
+	export class UpdateStatus {
+	    currentVersion: string;
+	    availableVersion: string;
+	    updateAvailable: boolean;
+	    checking: boolean;
+	    downloading: boolean;
+	    downloadProgress: number;
+	    ready: boolean;
+	    installerPath: string;
+	    errorMessage: string;
+	    releaseNotes?: string;
+	    lastCheckTime: string;
+	
+	    static createFrom(source: any = {}) {
+	        return new UpdateStatus(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.currentVersion = source["currentVersion"];
+	        this.availableVersion = source["availableVersion"];
+	        this.updateAvailable = source["updateAvailable"];
+	        this.checking = source["checking"];
+	        this.downloading = source["downloading"];
+	        this.downloadProgress = source["downloadProgress"];
+	        this.ready = source["ready"];
+	        this.installerPath = source["installerPath"];
+	        this.errorMessage = source["errorMessage"];
+	        this.releaseNotes = source["releaseNotes"];
+	        this.lastCheckTime = source["lastCheckTime"];
+	    }
+	}
 	export class ViewerData {
 	    imageData?: ImageViewerData;
 	    pdfData?: PDFViewerData;
@@ -717,6 +819,10 @@ export namespace utils {
 	    SDKDecoderReleaseChannel: string;
 	    GUISemver: string;
 	    GUIReleaseChannel: string;
+	    Language: string;
+	    UpdateCheckEnabled: string;
+	    UpdatePath: string;
+	    UpdateAutoCheck: string;
 	
 	    static createFrom(source: any = {}) {
 	        return new EMLyConfig(source);
@@ -728,6 +834,10 @@ export namespace utils {
 	        this.SDKDecoderReleaseChannel = source["SDKDecoderReleaseChannel"];
 	        this.GUISemver = source["GUISemver"];
 	        this.GUIReleaseChannel = source["GUIReleaseChannel"];
+	        this.Language = source["Language"];
+	        this.UpdateCheckEnabled = source["UpdateCheckEnabled"];
+	        this.UpdatePath = source["UpdatePath"];
+	        this.UpdateAutoCheck = source["UpdateAutoCheck"];
 	    }
 	}
 	export class Config {
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.24.4

 require (
 	github.com/jaypipes/ghw v0.21.2
+	github.com/teamwork/tnef v0.0.0-20200108124832-7deabccfdb32
 	github.com/wailsapp/wails/v2 v2.11.0
 	golang.org/x/sys v0.40.0
 	golang.org/x/text v0.22.0
@@ -30,6 +31,8 @@ require (
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/samber/lo v1.49.1 // indirect
+	github.com/teamwork/test v0.0.0-20200108114543-02621bae84ad // indirect
+	github.com/teamwork/utils v1.0.0 // indirect
 	github.com/tkrajina/go-reflector v0.5.8 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
 	github.com/valyala/fasttemplate v1.2.2 // indirect
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,4 @@
+github.com/Strum355/go-difflib v1.1.0/go.mod h1:r1cVg1JkGsTWkaR7At56v7hfuMgiUL8meTLwxFzOmvE=
 github.com/bep/debounce v1.2.1 h1:v67fRdBA9UQu2NhLFXrSg0Brw7CexQekrBwDMM8bzeY=
 github.com/bep/debounce v1.2.1/go.mod h1:H8yggRPQKLUhUoqrJC1bO2xNya7vanpDl7xR3ISbCJ0=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -47,6 +48,7 @@ github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWb
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c h1:+mdjkGKdHQG3305AYmdv1U2eRNDiU2ErMBj1gwrq8eQ=
 github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c/go.mod h1:7rwL4CYBLnjLxUqIJNnCWiEdr3bn6IUYi15bNlnbCCU=
+github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -65,6 +67,13 @@ github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
+github.com/teamwork/test v0.0.0-20190410143529-8897d82f8d46/go.mod h1:TIbx7tx6WHBjQeLRM4eWQZBL7kmBZ7/KI4x4v7Y5YmA=
+github.com/teamwork/test v0.0.0-20200108114543-02621bae84ad h1:25sEr0awm0ZPancg5W5H5VvN7PWsJloUBpii10a9isw=
+github.com/teamwork/test v0.0.0-20200108114543-02621bae84ad/go.mod h1:TIbx7tx6WHBjQeLRM4eWQZBL7kmBZ7/KI4x4v7Y5YmA=
+github.com/teamwork/tnef v0.0.0-20200108124832-7deabccfdb32 h1:j15wq0XPAY/HR/0+dtwUrIrF2ZTKbk7QIES2p4dAG+k=
+github.com/teamwork/tnef v0.0.0-20200108124832-7deabccfdb32/go.mod h1:v7dFaQrF/4+curx7UTH9rqTkHTgXqghfI3thANW150o=
+github.com/teamwork/utils v1.0.0 h1:30WqhSbZ9nFhaJSx9HH+yFLiQvL64nqAOyyl5IxoYlY=
+github.com/teamwork/utils v1.0.0/go.mod h1:3Fn0qxFeRNpvsg/9T1+btOOOKkd1qG2nPYKKcOmNpcs=
 github.com/tkrajina/go-reflector v0.5.8 h1:yPADHrwmUbMq4RGEyaOUpz2H90sRsETNVpjzo3DLVQQ=
 github.com/tkrajina/go-reflector v0.5.8/go.mod h1:ECbqLgccecY5kPmPmXg1MrHW585yMcDkVl6IvJe64T4=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=