[mikee4fun]

Its not rom specific at all. Its your Yahoo Pop account. This is what you can do and it will, fix your problem. Log into your Yahoo web mail and make a folder for a temporary basis. Say, Saved inbox. Move all your inbox emails to that folder. Log off you webmail and now, on you computer with any email client setup a pop account with the same email that you have setup on your phone. One setup, run it and let all email dump to the email client. Make sure you have the advanced settings selected to remove mail from server after downloading. This will purge the inbox on the yahoo or att yahoo pop server. With that said, you should now have a clean inbox. Now hard reset your phone and re setup your yahoo mail account. You should be good. Now log back into your yahoo web mail account and moved your saved inbox items back to your inbox folder not the saved inbox folder on the server. The question here is do you only use web mail and do you need to keep all your old email on web email? Are you cool with downloading it all to a local email client and purging it all together from web mail? Also you could have a corrupt email considering it is dumping all those emails to your phone. I have seen this many times. It is an easy fix, the question is do you care about keeping all your old email in your root pop inbox.

Oh and your phone is far from bricked, but with that many emails, hah you have no storage space left...