Deliverability
Backscatter
Bounce messages sent to forged sender addresses, often caused by spam or viruses using fake return addresses.
Definition
Backscatter refers to incorrectly addressed bounce messages sent to innocent third parties. It occurs when spammers forge the "From" address in their emails, causing bounce notifications to be sent to the forged address rather than the actual sender. Backscatter is problematic because it wastes resources, can be used for denial-of-service attacks, and may cause legitimate domains to be blacklisted if they appear to be the source.
Examples
A spammer sends 1 million emails with your domain as the forged sender, resulting in thousands of bounce messages flooding your inbox
Pro Tip
Implementing DMARC with a reject policy helps prevent your domain from being used in backscatter attacks.