Yes, this is expected because your domain uses DMARC. If it just send it without that, any hosts that check DMARC would possibly reject it. If it redoes the from it avoids this problem.

see:

https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/handlers/docs/dmarc-mitigations.html

Ah, I see. Is there something I need to change in my DMARC record? I do control the domain and thus the DMARC record, but I do not control the mail server.

I mean I see other domains on the mailing list (redhat.com, google.com) having DMARC enabled and no via devel suffixed to the name.

I just checked. At the beginning of July there was an issue with mail not being accepted (incoming and outgoing) by my mail provider for a short time. The issue was related to DNS (it's always DNS) and may have made some changes in an attempt to mitigate the issue. My DMARC record is currently set to:

v=DMARC1; p=reject; sp=reject; rua=mailto:postmaster@penguinpee.nl; rf=afrf; pct=100; ri=86400; adkim=r; aspf=s;

I don't have any record of what it might have been before, I believe. But I'll check.

I don't have any record of what it might have been before, I believe. But I'll check.

I do, It used to be:

v=DMARC1; p=none; rua=mailto:postmaster@penguinpee.nl; ruf=mailto:postmaster@penguinpee.nl; adkim=s; aspf=r

I'll have to look up what all those different values mean, though.

Yeah, it's only active for people with reject set... ie, telling other providers to reject any email that doesn't validate. With p=none it won't trigger.

Thanks, Kevin. I'll change it back to p=none and go through the other options while I'm at it to refresh my memory.