I have 5 active email accounts and typically I try to the proper address for the appropriate website. Sometimes the site accounts are older and I can search my inbox for the original email to see my log-in credentials. I know pre-iOS7 you could tap on your name in the email header and it would take you to your contact info and highlight the account the email was attached to. It seems it no longer does this. Instead of tapping through all the accounts one by one, is there something that does work?