Change user e-mail on login – LDAP

The question is actually quite simple, but I haven’t found a direction yet. Users in the LDAP domain we have are @abc.com emails and I need those emails to be “transformed” to @xyz.com after a successfull authentication.The closest I found was using functions.php but without success.

It seems I have to create a hook/filter do make that transformation, but don’t really know how to go from here.