I’m having trouble with emails delivered through Mailgun service ending up in the spam folder when sent to Microsoft Outlook users. I noticed that Mailgun automatically includes a tiny invisible tracking pixel (1x1 transparent image) in every email message for analytics purposes. I suspect this tracking element might be triggering Outlook’s spam filters and causing my legitimate emails to be flagged as junk mail. Has anyone else experienced this issue? What are the best practices to ensure better email deliverability and avoid spam folder placement when using Mailgun? I really need to find a solution because my users are missing important notifications.
Dealing with similar issues myself and found that content filtering can be just as problematic as authentication. Outlook gets particularly aggressive with certain trigger words and formatting patterns. Have you tried testing your email content through a spam score checker before sending? Sometimes seemingly innocent phrases can bump up your spam score significantly. Also worth mentioning that sending frequency matters a lot with Microsoft - if you suddenly increase your volume or send at irregular intervals, their filters get suspicious. I started warming up my sending patterns gradually and saw noticeable improvement. One more thing that worked for me was including a proper physical address in the footer and making sure the from name matches your domain identity. These small details add up when Outlook evaluates sender trustworthiness.
yeah, outlook can be tough on emails. defo check your SPF and DKIM settings. also, try sending to your domain first and build up to larger lists slowly. might help avoid the spam folder.
From my experience with Mailgun, the tracking pixel is rarely the main culprit for spam filtering. I’ve found that domain reputation plays a much bigger role with Outlook specifically. Make sure you’re authenticating properly with DMARC policies set up correctly - not just SPF and DKIM. Also worth checking if you’re sending from a subdomain rather than your main domain, as this can help isolate your email reputation. Another thing that helped me was monitoring Mailgun’s suppression lists and making sure bounced addresses get cleaned out regularly. If you’re still having issues, try reaching out to Mailgun support for a deliverability audit - they can spot authentication problems that aren’t obvious from the dashboard.