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I operate my own mail server at speedofsoundgaming.com and mwtd.net. I recently added a DMARC record to my domain to help prevent spam, and once seeing that things seemed to be working, upped the level to quarantine from none. However, I had not sent an email through a mailing list before doing this (I rarely use this domain for mailing lists anyway), but now when I send emails through a mailing list, it gets quarantined (so far as I can tell, so far from yahoo, and probably alot more). This, as you can imagine, is a big problem for me.

So my question:

Is there anything I can do to my DMARC record, apart from setting it to none (as that would defeat the purpose of DMARC to prevent spam) to let my emails go through when sent through a mailing list?

A little more info:

This email list also signs its emails using DKIM, but I believe that wouldn't really matter anyway because as they add a footer, etc my own DKIM signature would be invalid even if they didn't sign. I sign my emails using DKIM and have a valid SPF record in place, and both, along with my DMARC record, seem to work fine, according to things like verifier.port25.com, unless they're going through a mailing list.

masegaloeh
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Michael Taboada
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1 Answers1

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Unfortunately, it's a well-known fact that DMARC and some mailing lists are effectively incompatible.

The same problems originally stemmed from SPF itself, and have prompted mailing lists (as well as forwarding services) to implement a feature known as SRS (Sender Rewriting Scheme), which is a feature that must be implemented by the mailing list operators.

You additionally report that the mailing list you partake in invalidates your DKIM signatures. Indeed, if your DKIM signatures would still be valid when the emails are received at the final destination by a list recipient, then there wouldn't be a problem. However, unless you can compose and sign your emails in such a way as to bypass such invalidation, there is nothing that you can do, other than using a distinct domain name for mailing list interactions with a DMARC policy of none.

cnst
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    For more information on this subject, reference [Interoperability Issues between Domain-based Message Authentication, Reporting, and Conformance (DMARC) and Indirect Email Flows](https://tools.ietf.org/html/rfc7960). – jnaab Oct 08 '18 at 17:12