--- a/sat/core/exceptions.py	Wed Feb 26 15:54:43 2020 +0100
+++ b/sat/core/exceptions.py	Wed Feb 26 15:54:43 2020 +0100
@@ -123,6 +123,10 @@
     pass
 
 
+class NetworkError(Exception):
+    """Something is wrong with a request (e.g. HTTP(S))"""
+
+
 class InvalidCertificate(Exception):
     """A TLS certificate is not valid"""
     pass

--- a/sat/plugins/plugin_misc_download.py	Wed Feb 26 15:54:43 2020 +0100
+++ b/sat/plugins/plugin_misc_download.py	Wed Feb 26 15:54:43 2020 +0100
@@ -169,6 +169,17 @@
         except KeyError:
             raise exceptions.NotFound(f"No callback registered for scheme {scheme!r}")
 
+    def errbackDownload(self, file_obj, download_d, resp):
+        """Set file_obj and download deferred appropriatly after a network error
+
+        @param file_obj(SatFile): file where the download must be done
+        @param download_d(Deferred): deffered which must be fired on complete download
+        @param resp(treq.response.IResponse): treq response
+        """
+        msg = f"HTTP error ({resp.code}): {resp.phrase.decode()}"
+        file_obj.close(error=msg)
+        download_d.errback(exceptions.NetworkError(msg))
+
     async def downloadHTTP(self, client, uri_parsed, dest_path, options):
         url = uri_parsed.geturl()
 
@@ -189,6 +200,10 @@
         progress_id = file_obj.uid
 
         resp = await treq.get(url, unbuffered=True)
-        d = treq.collect(resp, file_obj.write)
-        d.addBoth(lambda _: file_obj.close())
+        if resp.code == 200:
+            d = treq.collect(resp, file_obj.write)
+            d.addBoth(lambda _: file_obj.close())
+        else:
+            d = defer.Deferred()
+            self.errbackDownload(file_obj, d, resp)
         return progress_id, d

--- a/sat/plugins/plugin_sec_aesgcm.py	Wed Feb 26 15:54:43 2020 +0100
+++ b/sat/plugins/plugin_sec_aesgcm.py	Wed Feb 26 15:54:43 2020 +0100
@@ -19,15 +19,15 @@
 import re
 from textwrap import dedent
 from functools import partial
-from urllib.parse import urlparse
+from urllib import parse
 import mimetypes
 import secrets
 from cryptography.hazmat.primitives import ciphers
 from cryptography.hazmat.primitives.ciphers import modes
 from cryptography.hazmat import backends
 from cryptography.exceptions import AlreadyFinalized
-from urllib import parse
 import treq
+from twisted.internet import defer
 from sat.core.i18n import _
 from sat.core.constants import Const as C
 from sat.core import exceptions
@@ -108,11 +108,15 @@
         progress_id = file_obj.uid
 
         resp = await treq.get(download_url, unbuffered=True)
-        d = treq.collect(resp, partial(
-            self.onDataDownload,
-            client=client,
-            file_obj=file_obj,
-            decryptor=decryptor))
+        if resp.code == 200:
+            d = treq.collect(resp, partial(
+                self.onDataDownload,
+                client=client,
+                file_obj=file_obj,
+                decryptor=decryptor))
+        else:
+            d = defer.Deferred()
+            self.host.plugins["DOWNLOAD"].errbackDownload(file_obj, d, resp)
         return progress_id, d
 
     def onDataDownload(self, data, client, file_obj, decryptor):
@@ -226,7 +230,7 @@
                 mess_encrypted = client.encryption.isEncrypted(data)
                 attachments = data['extra'].setdefault(C.MESS_KEY_ATTACHMENTS, [])
                 for link in links:
-                    path = urlparse(link).path
+                    path = parse.urlparse(link).path
                     attachment = {
                         "url": link,
                     }