I think we can close this BR, there is no such problem now. A setting has been changed to improve the situation and other changes are being discussed and tested in OVIRT-2717.

In response to these old mails Sam Cappello made a comment related to receiving mails from himself. I checked the logs and there are only 3 envelope-from him. I could not see more mails from him in the archive. And the database confirms what he said in his post that he did not post in the past, thus not something related to the 2016 mails being resent anyway. I can't find any trace of these offending mails at the moment, am I missing something?

Ref: https://lists.ovirt.org/archives/list/users@ovirt.org/message/GZYLXSCQZMLD7ATNCPAFWD3575WKYTST/

Also I was wondering about removing the duplicate threads from the archive. It might be a very annoying job and I'm not sure of the exact number but more than 100 over the last 10 days. It's possible to remove entire threads as site-admin, so it could help but that's still going to be annoying. I hope people are not replying to old discussion. Shat do you think?

Since the change ~3h ago I did remove the iptables rule and monitored the server. Unfortunately they are not sending again. I would have like to confirm this blocks all the mails properly. I'll continue to monitor.

From what I see in one of the mails there is a Received-SPF header, probably the original one, and after looking at why there is no SPF score triggered I stumbled onto the ignore_received_spf_header setting, which default to 0. As we rely on Spamassassin to do all the tests (as there is only one mail host, there would be no gain), then it is tricked into thinking all is fine.

I'm changing the setting right away.