I've had courier working well for a while, but all of a sudden any
connection to it takes a long time to be established, in the order of a
few minutes. This happens even when connecting to localhost or the
server's internal IP, for example:
telnet localhost 25
telnet 192.168.1.246 25
And connections from the outside also experience this problem.
In debugging the problem, I verified dns lookups, including reverse
lookups, and they seem to work fine.
Since this delay happens with localhost, firewall problems were ruled out.
I have a list of RBL hosts that get checked, so I decided to disable
the RBL checking to see what happens...
And that turned out to be the problem. :-(
When I disable the RBL checks, the timeout problem goes away.
I'd still like to be able to do RBL checking, however... Is there any way
to get around this problem?