I will care about documentation in OVIRT-974.

After some time no one reported any problem after the changes, thus closing.

https://gerrit.ovirt.org/#/c/91613/

Sounds good.
I think it will really help if we'll have a section on MM on infra docs [1], where we can add documentation about our mail service and links to relevant documentation and Ansible playbooks, WDYT?

[1] http://ovirt-infra-docs.readthedocs.io/en/latest/

We need to reevaluate this with the new system (MM3).

So currently Spamassassin tags considers SPAM when mails reach score 5. This can easily changed but I think it should be fine.

The system only tags SPAM, never purge, so users can use the tag to move mails in their spambox and check it from time to time. We could purge after a certain level. I created the Ansible rules for RDO with discard when score reaches 8 and noone complained. So we may add them to oVirt too if you feel it's fine.

So far I can say I haven't seen false positives on the spam filters I've seen, all were legit spam.
Mostly because the list doesn't have much traffic and the people who send to it are limited to a small group.