This check fires when the algorithm has predicted that it is likely that the provided email address is fake or automatically generated. There are two levels of sensitivity for this check.
Fraudsters set up scripts to automate the creation of email addresses. These email address may appear as gibberish or may be sophisticated enough to appear legitimate. Our prediction algorithm analyzes email address across our entire network and correlates certain attributes with fraud and known card-testing schemes.
There are two threshold levels for this check. This allows merchants to set different score modifiers depending on how likely the algorithm thinks the email is fake. Only the email addresses that meet one of the two thresholds trigger the check.