I'm working on converting to using postscreen. Studying the details. I have a question from the docs related to the delays due to the effective greylisting caused by "Tests after the 220 SMTP server greeting". I believe my server would qualify as a small site receiving mail for just a few hundred users.
Snippet from the Howto: " The following measures may help to avoid email delays: Small sites: Configure postscreen(8) to listen on multiple IP addresses, published in DNS as different IP addresses for the same MX hostname or for different MX hostnames. This avoids mail delivery delays with clients that reconnect immediately from the same IP address. Can someone help me understand why this helps? If I add an IP to the server and configure it as a second instance of the MX hostname, how does that help with a server that may reconnect from a different IP? I though tthat if it reconnected immediately from the same IP, that would be a good thing. Or maybe I misunderstood "immediately". I took it to mean immediately after getting a 4xx response and drop. I assume this doesn't do anything to help with servers like Google that will connect from a different server? Anyway, I'd apprecaite it if someone could elaboate so I understand this detail. Thank you, Scott
