Earlier quoted context omitted.
Alternatively setup your own free mailserver. Its always been a puzzle to me why so many people just don't own their own mailserver, just like you "own" your mail box at your property. You can use spamassasin which is as good as they come. Problem solved.
BTDT and it was a huge relief when I moved my domain to Google Apps and started using Gmail. Unless it's gotten hugely more effective than it was a few years ago, Spamassassin is nowhere near as good as Gmail at recognizing spam, and spamfighting was the biggest of many chores involved in running my own server. I was constantly having to tweak and refine things to keep my spam filtering effective. I don't miss runnin…
Instead I spend time tweaking fun stuff on my mail server, like setting-up X.509 user certificate-based authentication instead of IDs and passwords. And transparent on-server S/MIME [ de|en ]cryption using Anubis. Stuff that the big mass-market providers won't implement.