From 49f48340ac074ee0c2f8f22affe2c7b3b3c2a5e5 Mon Sep 17 00:00:00 2001
From: SuchAFuriousDeath <48620541+SuchAFuriousDeath@users.noreply.github.com>
Date: Mon, 9 Mar 2026 11:56:44 +0100
Subject: [PATCH] Fix attachment MIME type detection for non-image file types
 (#3604)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The mail parser's MIME type fallback map only contained image types (jpg,
jpeg, png, gif, webp), causing attachments sent as application/octet-stream
(common with Lotus Notes and other legacy clients) to be stored with a NULL
type. This made PDFs and documents download instead of opening inline.

Extended $extMimeTypeMap with common document, archive and media types.

Also fixed getAttachmentFilenameExtension() which used explode('.')[1] to
get the extension — this returns the part after the *first* dot rather than
the last, breaking for filenames like "report.2024.pdf". Replaced with
pathinfo() which correctly extracts the final extension.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
---
 .../Espo/Core/Mail/Parsers/MailMimeParser.php | 25 +++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/application/Espo/Core/Mail/Parsers/MailMimeParser.php b/application/Espo/Core/Mail/Parsers/MailMimeParser.php
index c14c2fde62..2ec7f40ecd 100644
--- a/application/Espo/Core/Mail/Parsers/MailMimeParser.php
+++ b/application/Espo/Core/Mail/Parsers/MailMimeParser.php
@@ -58,6 +58,27 @@ class MailMimeParser implements Parser
         'png' => 'image/png',
         'gif' => 'image/gif',
         'webp' => 'image/webp',
+        'pdf' => 'application/pdf',
+        'doc' => 'application/msword',
+        'docx' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
+        'xls' => 'application/vnd.ms-excel',
+        'xlsx' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
+        'ppt' => 'application/vnd.ms-powerpoint',
+        'pptx' => 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
+        'odt' => 'application/vnd.oasis.opendocument.text',
+        'ods' => 'application/vnd.oasis.opendocument.spreadsheet',
+        'csv' => 'text/csv',
+        'txt' => 'text/plain',
+        'html' => 'text/html',
+        'htm' => 'text/html',
+        'xml' => 'application/xml',
+        'zip' => 'application/zip',
+        'gz' => 'application/gzip',
+        'eml' => 'message/rfc822',
+        'svg' => 'image/svg+xml',
+        'bmp' => 'image/bmp',
+        'tif' => 'image/tiff',
+        'tiff' => 'image/tiff',
     ];
 
     private ?WrappeeParser $parser = null;
@@ -434,9 +455,9 @@ class MailMimeParser implements Parser
             return null;
         }
 
-        $ext = explode('.', $filename)[1] ?? null;
+        $ext = pathinfo($filename, PATHINFO_EXTENSION);
 
-        if (!$ext) {
+        if ($ext === '') {
             return null;
         }