[timmipetit]

Thanks for the advice, we've had some strange situations where our mails got marked as spam. Currently we only have issues with Outlook. Mails send using Mailgun often get marked as spam, while (the same) mails send using Gmail don't have this problem. Unfortunately, this doesn't seem to happen on all Outlook installations/instances, and Outlook is pretty much a black box to test. Perhaps this could be similar issue (we've had no issues on a clean Outlook installation). Anyone else with similar problems?