Connection to server is unavailable, please help.

Connection to server is unavailable, please help.

I seem to be having ongoing connectivity issues with one set-up. I use two different computers with two different versions of Outlook. The one I need to work seems to have frequent problems connecting to the server (IMAP).

I've checked and the settings are the same on both versions of Outlook. One works the other doesn't.
Any suggestions would be appreciated.

Thanks,

Jason