To control credit cards fraud at your store, be alert of orders that originate from email addresses issued by free hosting providers like yahoo.com, hotmail.com, etc. It is much better to simply not accept orders from email address originating at free hosting providers. While this may be extreme due to the widespread use of Hotmail and Yahoo addresses, it should at least set off some warning bells when combined with other warning signs.
The black e-mail list allows forming the list of suspicious domains and filter orders placed by customers that have specified such e-mail addresses while saving credit card in HSPcomplete.
To add a mail server to the black list: