New Users E-mail Banned during registration

[محروم.كوم]

My potential new users are getting the following error message when trying to register: The administrator has banned your email address. To contact the administrator click here


I am personally trying to register with a newly created yahoo account and am receiving this message. I do not have @yahoo.com banned in the Vbulleitin options. Is there another place where these e-mail addresses may be banned ? __DEFINE_LIKE_SHARE__