XF 1.5 Limit number of dots used in registration email addresses

Jim McClain

Nearly every day I get new registrations that use multiple dots in the username portion of their email address. Examples:


These are always bad actors that usually get sent to the approval queue but I would prefer they wouldn't even be able to complete their registration. Is there a way to block registrations from anyone using more than 2 dots in their email address username? Can I use something like ..@ in the banned email list? Is there a tip, secret or add-on for this?