I've checked your smtp server at imap.ooorah.net, and I could find out it is accepting messages:
pablob@medusa /home/pablob$ telnet imap.ooorah.net 25
Connected to imap.ooorah.net (18.104.22.168).
Escape character is '^]'.
220 ooorah.net ESMTP Postfix (2.0.11)
MAIL FROM: email@example.com
RCPT TO: firstname.lastname@example.org
354 End data with <CR><LF>.<CR><LF>
Testing your incoming box for linuxquestions.org
250 Ok: queued as A157937CAE
Connection closed by foreign host.
From the resulting session you can see my message was at least queued. You'll have to find out where it goes. Check within /var/spool/postfix/ , maybe there you can find the sequence number A157937CAE with my message.
As you say you can't also send, you must be receiving an error within any log file; check under /var/log/mail/ .
What about firewalling.
SSH ? As far as I know there's no relation within ssh & postfix. I don't use RHat so I can't help you with what goes on with redhat-switch-mail.