Thread:Project:Support desk/Username with @ sign inside

Hello, our usernames are taken from another application with the syntax "user@domain.de" ... this works perfect but if we try to change the userrights per specialpage, the mediawiki tells us its not possible because the user is not local ... it looks like he interpreted the @ as other domain.

How can i change the rules for usernames and allow the "@" signs in it?

Thanks al lot :)

Gerd