Account Issue with Email, very weird

Ok so My friend hasn't played in almost 2 years and we are all getting back on. But when he logs in his password isnt working, fine he trys to reset it with the send to email and it says it is not registered email account. The weird thing is he has the original email he used way back when confirming it is registered and good to go and it says its not registered When he trys to reset. We do not know how that happened and he swears by it that he has just the 1 email hes been using for 6 years. We started a ticket but people say it takes like 3 days or so so I was wondering if anyone else ran into this issue. Also side note we dont think his account was compromised at all either cause hes still in the guild, says he hasnt logged on in 590 days (which is about right) and his account isnt deleted like most peoples accounts who get hacked and banned.

Did he log in after FFXIV:ARR (2.0) gone live?

He may not have his account migrated over perhaps? He would have to contact SE Customer Service to look into this service account.