If you are allowed to ssh out, you can redirect your mail traffic through an ssh session.
For example, you could run the following command:
Code:
ssh -L 4110:your.mail.server.com:110 username@some-server.com
"some-server.com" could be any server to which you have ssh access, and does not have to be the same as your mail server (though that's fine if it is). After getting this set up, you would set Opera up to use localhost, port 4110 as the mail server. When opera connects to localhost, ssh will encrypt and forward the connection out through some-server.com and then to your.mail.server.com. This has the added side-benefit that nobody in your company can eavesdrop your mail traffic.
If I'm reading that nmap log right, it looks like you could do this, as ssh seems to be open.