How to Uncover Encrypted Email Address?

Hey All,

I need to log-in to an old forum account that is no longer moderated. I remember my username and password but the website is restricted to email log-in entry only:

~Email

~Password

instead of...

~Username

~Password

It is legit the opposite of the way NullByte works. This site asks for your username, but the site I am trying to access asks for your email instead.

Is there any work-around for this? I just need a way to access the email linked to a given username. What sort of encryption is used to perform this hiding of emails?

Cheers if anyone can assist!