I am trying to set up osTicket 1.10.  For some reason, osTicket does not seem to think .biz is an acceptable top-level domain name for an email address.  I have tried to have multiple users in my company open a new ticket as a guest user, however, when entering their email address which ends with .biz, they are greeted with the error message "Enter a valid email address".  If I enter an email address ending with .com the ticket is created with no problems.Any help on this would be greatly appreciated.