Set your email account to poll the server every 15 mins. Then set your
inbox to the SMS tab and switch to another application.
Wait 15 mins for your phone to poll your email server.
Notice, that the email server never gets polled. Your email is never
automatically download!!
I think this happens because if you do not leave your inbox tab on your
email account that email account is not active. You can confirm this by
running Task Manager. If inbox is set on the SMS account, only SMS is
active. If MMS is selected then only MMS is active.
So we have the following problems:
1 - If you do not leave your inbox on the email tab, emails will not be
downloaded automatically.
2 - If you have multiple email accounts only one account can
automatically download email because you can only select one inbox tab
at a time.