I've read the manual and the solution it gives me doesn't work, simply because I don't have those options available in my phone.
It tells me to go to: Messages > Options > Email Settings > Mark Send email to Handheld to "NO"
But I don't get the "Send email to Handheld" anywhere. All the options I get in Email Settings is "Enable HTML Email" (which is marked as "NO"), "Confirm Delivery", "Confirm Read", and "Send Read Receipts".
did you set up your email via phone? if so go back into the email settings, log in and delete the email accounts you dont want sent to your phone any more.