I just came up with an idea for our mails at work. We’re battleing spam every day and received more than 23 mio spam mails for 2006 so far. Good spam filters are most of the time very expensive.
What we did now is.. setting a gmail account in between:
One catchall address on our mailserver -> mails are getting forwarded to gmail -> gmail forwards the mails back to our postmaster address -> our local mailserver routes the mails to the proper persons
There you go, you probably can’t get a better spam filter for free as the one from Google.
PS: We don’t care about delivering our mail through Google but it’s eventually not that good for Yahoo or MSN employees 😉