Reverse DNS Lookups

[Eric Gregory]

Any help on this is much appreciated, I've just begun using qpopper on my freebsd 4.5 postfix 1.1.11 server, For the most part I've been very happy with the results except for one quirk, Qpopper seems to be running a reverse DNS query for every connction, most of the time this hasn't caused a problem but some of my users are connecting from IP's that for some reason don't have a Reverse DNS entry  The result is that these users do get connected but there's a 20 to 30 second delay before they do, is there any way to either eliminate the Reverse DNS lookup or just shorten the timeout so that instead of waiting 20 or 30 seconds it only waits 3 or 4.   I've kind of come to this conclusion by elimination, The only thing I can find in common with the hosts that are having this problem is that there is no Reverse DNS for them.   THanks Eric Gregory