Can't access to my account, email provider has closed


I’m having the same kind of issue: I can't login to my account because my email service provider doesn't work anymore

I am the owner of this profile:
It is associated with an address, this provider has closed and I am lock-out of my mozilla account.

I logged-in with my Github account to publish a contrib on MDN. So, I have now 2 accounts.

Is there a way to regain access to my old account? Maybe to “merge” them? Or is it lost forever?

Thanks in advance!