Hello support.
Following setup.
domain.com is a standalone domain
alias.de is an alias domain of domain.com
group1 is a group added to domain.com. Members are allowed to use this address as a sender email address.
user1 is a user created on domain.com and a member of group1
SPF, DKIM, and DMARC are all configure correctly and work as expected for both domain.com and alias.de, when the sending email address is user1@domain.com or user1@alias.de. It also works fine when sending from group1@domain.com
The problem is, when sending from group1@alias.de DMARC fails. Basically I noticed that the Sender in the Email Header is set to user1@domain.com, even though the From value in the Email Header is set to group1@alias.de. What happens as an effect, is that DKIM and SPF are matching with domain.com, and DMARC fails as it expects alias.de.
Is there any way to fix this problem? Or is this a bug? I’ve been actually experienced this for a couple of versions now, so I’m confident it’s not a recent development. If it’s intended behavior, it pretty much makes the use this group as a sending email address option useless. I tried a bunch of things, but I can’t seem to find a way to rewrite Sender in the Email Header. But maybe there’s a better option to address this. Please let me know!
Thank you in advance for your help!