I had this problem a while back, as well.
Regardless of the service you're using, you need these settings for your outgoing setup:
username: blank
password: blank
Outgoing mail server: cwmx.com
Access Point in use: whatever you want to use
Security (ports): off
This is a recent change, as I used to be able to use gmail's outgoing server and send just fine. Anyways, I send and receive all day long with these settings, no problems. Only downside is that emails sent from your mobile will NOT show up in your sent items on the webmail.