I want to run on a subdomain my own mailman installation. I have successfully build everything up and it runs smoothly. But the DMARC settings nack me - if the recipient takes care of such settings the mail will be blocked.
My question now - how can I run a Mail system on the external System for a Subdomain?
example.org. The Subdomain
mailman.example.org points to a different host, having
MX records set up in the custom DNS Settings.
Receiving emails is possible, but because the subdomain is not excluded from DMARC and/or
mailman.example.org is a valid sender the mailman server can’t reach all recipients.
How can I configure either the DMARC settings to make
mailman.example.org valid or make it possible to relay all messages via the MIAB. With the second option - creating one account/alias for the subdomain on the box MIAB will overwrite the MX Records added adds itself with the priority of 10. What makes the MIAB a Backup/secondary MX for that Domain what is not wanted (as I would need to configure fetchmail for that box to get even the mis-redirected messages to the lists.
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When I try to override the DMARC Settings the result is something inconsistent. Because the Domain holds two DMARC Records now …