[fdo] PSA: Google dropping a lot of list email

[Daniel Stone]

Hi all,
There's a good chance that the people who most need to see this won't
see it, but here goes anyway.

Google is currently dropping a _lot_ of the mail we attempt to deliver
to lists.fd.o subscribers. The immediate cause is sending on mail from
domains with SPF/DKIM/DMARC policies which explicitly specify that
lists.fd.o cannot relay mail on their behalf. Every time we do that,
not only do those mails get dropped on the floor by Google,
Outlook/Office, and pretty much every large mail provider, but at
least for Google this seems to really push fd.o's sender reputation
down.

I have contacted those from the responsible domains (and temporarily
blacklisted them from sending any mail as an urgent fix), as well as
tried to make contact with Google directly, but until our reputation
recovers, Google appears to be dropping a lot of the messages we
attempt to deliver, even from domains which do not have restrictive
sender policies.

If this gets much worse, we might need to temporarily suspend all
delivery to GMail for a while and hope that the policies time out and
return to normal delivery.

In the meantime, if you are on one of these hosts and missing random
emails from lists, at least you know why.

Cheers,
Daniel