--- a/sat/core/xmpp.py	Sun Feb 23 17:49:21 2020 +0100
+++ b/sat/core/xmpp.py	Wed Feb 26 15:54:34 2020 +0100
@@ -23,6 +23,7 @@
 import mimetypes
 from urllib.parse import urlparse, unquote
 from functools import partial
+from pathlib import Path
 import shortuuid
 from sat.core.i18n import _
 from sat.core.constants import Const as C
@@ -1133,10 +1134,11 @@
         """Complete missing metadata of attachments"""
         for attachment in data['extra'].get(C.MESS_KEY_ATTACHMENTS, []):
             if "name" not in attachment:
-                name = unquote(urlparse(attachment['url']).path.rsplit('/', 1)[-1])
+                name = (Path(unquote(urlparse(attachment['url']).path)).name
+                        or C.FILE_DEFAULT_NAME)
                 attachment["name"] = name
             if C.MESS_KEY_MEDIA_TYPE not in attachment:
-                media_type = mimetypes.guess_type(attachment['url'], strict=False)[0]
+                media_type = mimetypes.guess_type(attachment['name'], strict=False)[0]
                 if media_type:
                     attachment[C.MESS_KEY_MEDIA_TYPE] = media_type
         return data