to recieve mail, do i have to have the imap ports (imap and imaps) open to the public? i cant figure out for the life of me why i cant recieve email. i have port 25 open on the server and i have port 25 forwarding to the email server, i can send mail and i can see in the router log file that there are hits comming in for port 25. when i telnet to port 25 from the server, i can get it but i cant telnet to it from the outside ( i sshed into a remote machine then used telnet from that machine). i even did this with no firewall..lemme turn taht back on...do you need udp and tcp for smtp? And finally, what log do i check to see if a request for port 25 actually hit the server....i see them hitting the router, but dunno how to check to see if they get to the email server.

thanks

To receive mail you only need tcp port 25 open.
Depending on the server, it may need udp port 53 open to make dns queries against people sending mail to you.

If you can tenet to port 25 ok internally, but not externally, you will need to trace the packets in & back out.
Usually an iptables/ipchains -j LOG rule in the INPUT & OUTPUT chains will tell you what's happening, eg
iptables -I INPUT -p tcp --dport 25 -j LOG --log-level 6 --log-prefix "smtp_in "
iptables -I OUTPUT -p tcp --sport 25 -j LOG --log-level 6 --log-prefix "smtp_out "
tail -f /var/log/messages to view the entries

Make sure your smtp server has it's gateway set correctly to the router address.

What smtp server are you using?
Log files may be in /var/log/maillog