back to wow

so after a long break i came back to wow and i see that my passwords aren't working. ive been playing since it was named frozen wow than molten wow and now warmane so yeah ive been here for a long time and i have forgotton what emails i used for every accounts, but i have mult accounts and this being one of them i also keep a list of my mails . i have 5 accounts 1 was long forgotten but i remember 4 because i use them everywhere . so heres the things, since i came back to warmane i notice my passwords arent working no i havent changed them nor have shared. i manage to recover 3 accounts but i am unable to retrieve my 4th account so i need help a hint of my email or something because maybe my ids has been breezed due to not being active for long. i need all my accoutns so help me up devs... ty
recently recovered ids :
_____, ______, ______ ( all mails were on the list of saved mails so i manage to recover these ids )
account that is unable to recover : _____ ( need hint of gmail orsomething )