By default when the `hamtrap` alias is enabled for a virtual server, any email sent to it will be added to SpamAssassin's learning database for the user who forwarded it. However, this option can be used to also add the original senders of the messages to the system-wide or domain-level whitelists, so they are never classified as spammers in future.

This can be useful if you have legitimate senders who are being incorrectly classified as spammers.