What is a Reverse NDR AttackThe non-delivery report (NDR) is generated when an email message is not able to be sent to the next hop.
Spammers can use NDR as a method to generate spam towards victims by using the victim's email address as the sender. This is called a reverse NDR Attack.
Consider the following scenario:
Refer to the diagram below for more information:
Preventing such attacks in XeamsThere are two features in Xeams that will help against a reverse NDR attack.