On Mon, 2007-02-05 at 11:25 +0000, David Woodhouse wrote:
The point in greylisting is very simple: it's to check that the mail is coming from a 'proper' mail server which actually does retry mail when you give a temporary rejection. Some people naïvely delay all incoming mail (and some outgoing mail too, if they reject at RCPT TO and the recipient uses callouts) by greylisting indiscriminately. I prefer mail to be fast in the common case, so I like to delay _only_ mail which actually looks suspicious in some way, and I prefer _never_ to greylist mail from a host (IP address) which was already observed to retry in the past.
Note that you should probably only pass at greylisting if an IP is not from one of the "known" ranges of dynamic IPs.
Nils