Mail admins should really learn to configure their MTA's to actually do something useful, and not just pass mail.
There are many sanity checks one can perform before the email is allowed to pass, and depending on how strict you go, you can eliminate 90%+ spam right there.
To effectively send spam, spammers reconfigure their mail servers, and make them not follow the rules. Yet most receiving mail servers simply accept all mail and let the spam checker deal with sorting the spam out. Why? Why not set up some ground rules?
See this or this page for an example configuration for postfix. Note that one doesn't have to use the RBL checks or any others that you normaly use or allow for your network. Tailor it for your needs. After all, you're in control. Right?
Comments
Auto-Mail delete ???
Well, here in Germany the law forbids the deleting of other people's personal mail. That law (secrecy of the post) handles letters in the first place but has to be obeyed also for emails.
So therefore marking a mail as spam is ok, but deleting it is not.
Guess that when they made this law, spam was only known as something to eat.