I've installed postfix with this nice tutorial http://wiki.centos.org/HowTos/postfix and postfix and dovecot are up and running. I set up user maildir as tutorial suggested. Now I can check my messages by windows email client via POP3. There are none yet. But when I'm trying to send email to this server via other mail service, it don't come. I suspect that I should open SMTP port on my server. When I try to
telnet myserver.com 25
I get nothing.