[otrs] Customer Signup Spam

Greetings, Our customer-side interface (customer.pl) is getting sign-up spam, causing generation of useless users cluttering the database as well as generating bounce tickets into OTRS (as they are using invalid email addresses). Is there some way to control domains allowed to sign up, or some other anti-registration spam control? We can't be the first people to have this problem, given how bad the spam-bot problems are on the Internet these days! Thank you, -- --- - Nick Bright Network Administrator Valnet Telecommunications, LLC Tel 888-332-1616 x 315 Fax 620-332-1201