what email client are you using? It's not a set up with your phone I believe, but rather a set-up with the actual email account's forwarding settings. Yahoo and Gmail have that feature.

Hi, my phone was set up by a friend who set it to copy my emails from my own email address to an o2 email address. I cannot for the life of me figure out how to change this. I don't need the o2 email account, the mailbox on it is full and sends email senders a "mailbox full" message, even though I'm getting them at my own email address. o2 say the account needs to be dormant for 90 days before they can close it, but I can't figure out how to stop emails going to it!!! Can anyone help?