Need help finding mules.

I quit RotMG a while ago and I'm thinking of starting up again. I've found out one of my mules and I don't remember the emails for the others.

I'm wondering if theres an account username database that I could search for my mule name? There probably isn't lmao but I don't know what else to do.

Have an old Muledump or something like this? Than search for this. But I think there is no other (public) way.