Unable connect to pop server with qmail
 

I have used RedHat 3 on my server and I installed qmail without problem. When I sending/receiving mail this message appear "Could not connect to POP server" . Althought I start qmail why this message appear.

Any help me, please.

Try doing a telnet session to your POP3 port. For example...

[root@falcon root]# telnet localhost 110
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
+OK <xxxxxx.xxxxxxxx@yourdomain.com>
user you@yourdomain.com
+OK
pass your_password
+OK
quit
+OK
Connection closed by foreign host.

For the username, it should probably be the full email address, but that may depend on what howto you used when setting up qmail.

You may also want to run the command...

/var/qmail/bin/qmail-showctl

and post the output here for us to see.