I use my own MX rubber-banded together with Postfix, SpamAssassin, and dovecot IMAP. I also have bucket.mydomain pointed to mailinator.com so I can use addresses under that domain as throwaways without the site I'm signing up for knowing about it, although I also use Postfix aliases for long-term throwaways.
My coworker runs his own MX, but bounces all his mail through Google just for the spam filtering.
My coworker runs his own MX, but bounces all his mail through Google just for the spam filtering.