Reverse DNS is a feature that a lot of mail servers use to reject spam. What it means is that if you ping say
www.infopop.com it comes up with an IP address say 10.0.0.1. Now the reverse dns means that if anyone wants to translate this IP address it must come back as
www.infopop.com. You can check if your mail server has the reversedns feature using tools located in
www.dnsstuff.com. If it is not then you must contact your ISP so that it can enable this feature for you.
I know for sure that AOL uses this reversedns feature to block spam and if your boards send quite a bit of emails to AOL users you will find yourself blocked as a spammer.
