updated mailbox app password

internal/smtpserver/attachments.go

@@ -2,6 +2,7 @@ package smtpserver
 
 import (
 	"bytes"
+	"encoding/base64"
 	"io"
 	"mime"
 	"mime/multipart"
@@ -84,6 +85,11 @@ func parseMessage(raw []byte) (*parsedMessage, error) {
 				break
 			}
 			data, _ := io.ReadAll(part)
+			// multipart.Reader auto-decodes quoted-printable transparently during Read,
+			// but not base64 (see the mime/multipart docs) — without this, a base64
+			// attachment/body part is stored/relayed-for-display as raw base64 text
+			// instead of its actual decoded bytes.
+			data = decodeContentTransferEncoding(part.Header.Get("Content-Transfer-Encoding"), data)
 			disp, dispParams, _ := mime.ParseMediaType(part.Header.Get("Content-Disposition"))
 			partCT := part.Header.Get("Content-Type")
 			partMediaType, _, _ := mime.ParseMediaType(partCT)
@@ -107,3 +113,29 @@ func parseMessage(raw []byte) (*parsedMessage, error) {
 	out.BodyText = strings.TrimSpace(out.BodyText)
 	return out, nil
 }
+
+// decodeContentTransferEncoding decodes a MIME part's body per its
+// Content-Transfer-Encoding when that isn't already handled transparently by
+// multipart.Reader (which only auto-decodes quoted-printable). base64 bodies are
+// wrapped at a fixed line length, so whitespace/newlines are stripped before
+// decoding. Falls back to the raw bytes on a decode error or any other encoding
+// (7bit/8bit/binary need no transform).
+func decodeContentTransferEncoding(cte string, data []byte) []byte {
+	if !strings.EqualFold(strings.TrimSpace(cte), "base64") {
+		return data
+	}
+	cleaned := make([]byte, 0, len(data))
+	for _, b := range data {
+		switch b {
+		case ' ', '\t', '\r', '\n':
+			continue
+		default:
+			cleaned = append(cleaned, b)
+		}
+	}
+	decoded, err := base64.StdEncoding.DecodeString(string(cleaned))
+	if err != nil {
+		return data
+	}
+	return decoded
+}