1) We will not issue patches for a specific fix. This is because of the complex nature of how we check all of the components, ie postfix, lucene, mysql, etc. There's a bug open for it, you might want to vote for it.
2) We have a public p4 cache that we're prepping to release. It isn't that we pulled it to piss people off...it's that it was a hassle to keep in sync. We have a new method, and it's in testing.
3) You can also change the password for them, if needed.
4) Mstreet: Perhaps sendmail is more to your liking. In case you have trouble finding their forum, here's a link:
http://www.tek-tips.com/threadminder.cfm?pid=14 I'm sure they'll meet your strict, open source, free requirements.
5) Apollo: in the announcements forum, right hand side, you'll see a Forum Tools link. Click on that and choose Subscribe. I've included a pic for you.