Trouble you can call to AT&T EMAIL customer service number 1-888-521-0120
Have you moved some of your important emails to your thrash folder and now open thrash folder to open that mail? Remember, mail does not remain in thrash folder for more than 30 Days. It gets deleted from there. Therefore, move that mail to inbox.
Visit :-http://www.contactlivesupport.com/att-mail-customer-service.html