David Beveridge wrote:
I'm happy to leave the definition of spam to spamassassin, and leave Mr Bayes to do my thinking for me.
And therein lies the problem. Unfortunately spamassassin is not really the best way to stop spam. You need more.
Speak for yourself. Spamassasin does a pretty good job for me.
Spamassassin should just be a tool in the toolkit not the entire solution. It is CPU and bandwidth intensive.
I get about 300 emails a day on my small system, of which about 150 are spam, as defined by SA. I don't think this is likely to burn out my (ancient) CPU.
A large proportion of spam can and should be rejected, before the body of the email is received.
I'm sure if and when such a system becomes available RedHat and CentOS will implement it, and I shall take advanage of their expertise.
I assume you are speaking of a system with hundreds or thousands of users. (Do such systems still exist? I thought they had died out.) I have 4 users. Our needs are very different.
Incidentally, I get email from sources who filter out spam, eg my college, and they don't seem to do a much better job than SA. I'm still invited to marry beautiful ladies from Russia.