WPMU sends emails to users with the SERVER_NAME, instead of the Site name!

Hello everybody,

I´ve got an issue about emails:

This issue appears only in the profile page, when the users change their email: they recive the mail from WPMU as "unknow sender", and the name of the Server instead of the Site name.

I´ve been many time looking for a solution but I can´t find the way to change it.

I would appreciate your help,

Thank you,