It looks like the Apple Mail application is not using the system's proxy settings. I have configured the proxy in the network system preferences, and all of my web browsers (Safari, Chrome, Firefox) are using these settings, but Mail.app doesn't seem to.
I've tried to connect to an IMAP server, but the request always times out. When I check using netstat, I can see that Mail.app is trying to directly connect to the IMAP server without going through the proxy.
Is there a way to force Mail.app to go through the proxy?
This is on Snow Leopard.
Best Answer
Use ProxyCap. Add there a "redirect" rule for the Mail.app bundle.
Note that a regular HTTP proxy will not work for Mail.app. You will need one of the following: SOCKS, SSH.