A forum member recently contacted me by the forum mail system asking if there was a way to check which email address they signed up with and change it if it was incorrect.
The answer is yes. If you go to profile>identity, you can see what mail address you signed up with and there is an option to change to a different one.
I answered the email I was sent about this, however manifestly if the email address said person is using is indeed incorrect they will not get my reply (since the forum forwards a notification and email to the registered email address for that account).
I would contact the member via private message, however as they are using the forum mail system, I would guess they do not check their private messages.
so, here is the confirmation for the person who contacted me whom I am not naming in case they wish to keep the fact that they're in technical difficulties quiet.