Mailgun forwarding can result in your domain being treated as spam

Hi All,<p>Mailgunner here, a couple of notes:<p>* The case outlined in this blog post is related to incoming email forwarding feature, not Mailgun outbound sending.<p>* General email forwarding case does not break Mailgun&#x27;s DKIM signature.<p>* Forwarding is tricky as long as it modifies content and we have lots of edge cases with our customers, and we are always working on improving on edge cases like this one.<p>* This is an edge case where the email has been forwarded from Mailchimp -&gt; Mailgun -&gt; Gmail and we have some conflicting content with Mailchimp&#x27;s original email causing the DKIM signature failure.<p>* Mailgun sending pipeline team is looking at the issue to get more detail about that.<p>Thanks everyone!

I had some problem with my mailgun-sent emails being marked as spam. But I was only using the free plan, since I only send 25 mails a week or so.<p>I didn&#x27;t have any problems with DKIM, though, or SPF. My problem was having to use a shared IP (part of the free plan) and sometimes getting an IP that was in one of the spam blacklists.<p>I&#x27;d add that <a href="https://www.mail-tester.com/" rel="nofollow">https:&#x2F;&#x2F;www.mail-tester.com&#x2F;</a> was INCREDIBLY useful when I was trying to diagnose problems.

As an aside, since Mailgun was bought by Rackspace, customer service, reliability, and their ability to fix issues quickly has seemingly taken a huge hit.<p>I couldn&#x27;t have been happier with Mailgun a year or so ago. Currently, I have a bug filed and reported to them that impacts our business (as well as many others I&#x27;m sure), that has been outstanding since <i>July</i>. They still haven&#x27;t acknowledged it - and all I get is stock responses linking to their <i>broken</i> documentation<p>Can anyone reccomend any alternatives? When we set up OpenRent in 2012, Mailgun was the best. Now I&#x27;m much less convinced - any feasible alternatives would be much appreciated.

Another thing to do: if your mailgun email to gmail gets inexplicably marked as spam (as opposed to DKIM failing), try creating a new fresh gmail account and see if email to that gets marked as spam. I was using an old gmail account and its filters were full of cat fur, which was causing stuff to randomly get marked as spam. Spent days playing high-low game deleting parts of the message then adding parts back in trying to figure out which words were triggering it, and it was totally non-deterministic. But once I switched to a fresh gmail account, it worked just fine, and nothing went into the spam folder.

&quot;The lesson we learned from this is that we should separate our transactional mail domain from our &#x27;real email&#x27;.&quot; Yes. Especially if your &quot;transactional email&quot; contains anything which could be interpreted as advertising. Many companies interpret &quot;transactional email&quot; as &quot;spamming our existing customers&quot;. Bayesian filters interpret this as spam.

Out of interest, are a lot of people using Mailgun for incoming email forwarding?<p>We do it because (1) Mailgun is great, and (2) it supports catch-alls, so for example, &#x2F;(.*)@foo.com&#x2F; goes to $1@bar.com. This allows our company to have one Google Apps account, but multiple email domains. Our DNS provider, Gandi, has email forwarding but not support catch-alls.<p>My understanding is that this is not precisely Mailgun&#x27;s intended purpose, but that it&#x27;s fine.

I&#x27;m curious to know whether you&#x27;ve experienced this only on your account and&#x2F;or if you tried to replicate this on a different account? Strangely enough I&#x27;ve not had problems with it although I understand the duplicate header might be troublesome..

Ouch... As one who was signing up for mailgun tomorrow, thanks for pointing that out.