wykyd,
Can you confirm a connection on port 110?
In windows:
start/run type: cmd
at command line prompt, type: telnet 110
should look like this: telnet xxx.xxx.xxx.xxx 110
Try again using your SME internal IP address to see what should happen.
You will see an immediate response if it connects to a mail server. The cmd box will be frozen, so just close it. You will get a time out after a long time if the connection fails.
If this works, but your client does not, your problem is likely the client..or possibly firewall software. I have found Norton firewall to cause issues with POP3 clients. But since your using SME, you really don't need a software firewall.
ryan