SpamAssassin

Each rule that matches adds or subtracts points, and a message over the threshold, five points by default, is marked as spam. Mail administrators tune the rules and the threshold, so results vary between sites.

Not related to verification. Running a draft through it shows content that scores badly, which is one input among many for real providers.

• Email filtering
• Email testing
• Spam
• Verify a list
• Topic: Spam and blocklists
• Topic: Email tools
• All terms