(See the best response by Higoten.)
So Byond asked me to change my password when I had it since 2008 and now I forgot it (Thanks Byond T_T) So Now I'm trying to recover it but I can't because I forgot my old email. I was wondering if anyone from the byond staff could send me a recover password thing on my new email. Thank you for reading!

E-mail: [email protected]
Byond Account: 5ratsuperhalo
Best response
Hi KomuruZukitaki,

Since you are unable to complete the automatic account recovery process, you should fill out the support form to begin the account recovery process. You should include any relevant information that may help confirm that you actually possess that account, and you will receive a private response via email within some reasonable amount of time.

Good luck!
I sent them a Message before :o Also I don't know how to let them know that it's my account o.o Anything specific I have to say?
I myself have had a similar problem, and the BYOND staff acted fast and professionally, and I was able to get my account back shortly after.

In my experience, it seems that logs are created that keep track(not sure if via IP address or computer id) of who logs on which key, and account activities. They were able to tell, just by my original key and another one that I used multiple times, that I was indeed the owner of said key, due to recent account activities.

Once they verified that I was the owner, they asked me if I wanted to change my original email address on my key, as I had forgotten the password for my original email as well. I was then able to send a password recovery link to my new email and change the password to my account.

Hopefully your experience is as smooth as my own (: