I have discovered greylisting, and it’s fantastic for fighting spam! It basically gives the sending mail server a “temporary unavailable” message the first time it talks to your server to send an email to someone. This means the sending mail server will then retry (as it’s a ‘temporary’ message and not permanent failure), but the email gets accepted the next time (after a time period specified, I have 1 minute), and any other time 1st time when they send in future.

The key:Most spammers don’t try twice!

I’ve had people moan about delays when recommending it. IMHO any well configured mail server should be configured to retry after several minutes. If not, it’s not my problem! A few minute wait isn’t no where near as much of a problem as a hell of a lot of spam is.

I have recommended this to work who are now implementing it as well. It’s cutting the amount of emails received by 98% (on their servers and mine)! Bloody impressive it is

Such a simple but effective idea.