Merge branch 'stable' into develop

diff --cc mailstream/mailstream.php
index 8bce2529eb7ef64defe39008dab59cc4bc3dca75,4056aac61359e11521036a05cb2e26971f242c1e..cc283789d3fdbfd3d2e3bbd3d96099d8a6160dd9
--- 1/mailstream/mailstream.php
--- 2/mailstream/mailstream.php
+++ b/mailstream/mailstream.php
@@@ -199,8 -220,13 +199,13 @@@ function mailstream_do_images(array &$i
                $cookiejar = tempnam(System::getTempPath(), 'cookiejar-mailstream-');
                try {
                        $curlResult = DI::httpClient()->fetchFull($url, HttpClientAccept::DEFAULT, 0, $cookiejar);
+                       if (!$curlResult->isSuccess()) {
+                               Logger::debug('mailstream: fetch image url failed', [
+                                       'url' => $url, 'item_id' => $item['id'], 'return_code' => $curlResult->getReturnCode()]);
+                               continue;
+                       }
                } catch (InvalidArgumentException $e) {
 -                      Logger::error('mailstream_do_images exception fetching url', ['url' => $url, 'item_id' => $item['id']]);
 +                      Logger::error('exception fetching url', ['url' => $url, 'item_id' => $item['id']]);
                        continue;
                }
                $attachments[$url] = [