Verify that your outgoing SMTP settings are the same on the phone as they are on the iPad. Also, if you are getting an error when attempting to send mail, what is the exact error you are receiving. Is the iPad also one that works on cellular, or is it a wifi only iPad?
I have only wifi on both, and first i had a message that the server is not accepted and second no message but also no sending :-) All settings are the same, did it for a several times.
Thank you for your feedback also
I recommend that you check back with your email provider and verify all of the required settings. Delete the mail account from the phone, do a reset on the phone, holding the sleep/wake and home buttons together until you see the Apple logo and then release. After the phone restarts and you have the verified settings for the mail account, add the account back to the phone and see if it will work. If not, come back and we can try and work through it.