It is probably a good idea to start implementing some of the antispam tools usable by domains; e.g. DKIM, SPF.

DKIM

[http://en.wikipedia.org/wiki/DomainKeys_Identified_Mail]

Gmail signs all its outgoing mail with DKIM.

Incoming

Checking DKIM on incoming messages? Job of MTA or MUA?

Mailman breaking existing signatures

Outgoing

There's a few milters, need to pick one.

SPF

SPF seems a bit more likely to cause Issues. None of the big providers seem to have hard FAIL policies yet.

Incoming

Do we want to add verification checks to incoming mail? Does it matter? Would have to be on ext-mx only (or maybe whitelist 130.95/16).

Outgoing

No mail goes out RESNET, so could publish 130.95/16 with SOFTFAIL (or even hard FAIL?)

Should we start doing SRS on .forward files?

Does anyone use their personal mail server to send mail with a UCC from address? Gmail doesn't matter because that uses the Sender header and a sensible envelope header.