This will be a list of telephone numbers you would never want to ring your phones. Blacklist applies account wide, so if you have multiple telephone numbers with PCS1, all callers in your blacklist will automatically go to voicemail when they call your service lines. If you have 1+ phone numbers with eFax service, the system will still listen for a fax tone, and if it doesn’t hear one, it will send the caller to voicemail just as they would no matter the phone number they call. You must provide the full ITU standard number. Therefore, calling 412 555 1212 will have to be entered as +14125551212.