Secure Mail Key Added Without My Permission
For the 2nd time now a secure mail key has been added to my AT&T email account without me initiating or requesting this to happen. I have a screencap of it but I cannot reach anyone at AT&T (I don't pay for any services - this is a free email account). Unfortunately I do still have a couple of legacy accounts attached to my @att.net email address and it will take me some time to change them over.
Can someone tell me how this is possible/how it was accomplished and whether I should be concerned about potential account compromise? I changed my login password after the last time but that doesn't seem to have helped.