What happens technically when a user marks an email as spam?

When a user clicks the spam button, multiple technical processes activate:

The message moves to the spam folder and the user's personal filter learns to distrust mail from that sender. Future messages from the same domain may go directly to spam for that recipient.

The complaint feeds into aggregate reputation data. The provider adds this signal to the sender's overall trust score, affecting deliverability to all recipients.

If the sender is enrolled in a Feedback Loop, the provider generates an ARF report containing the complainant's address and message details.

Machine learning systems may use the complaint to train content filters, learning to recognize similar messages as unwanted.

Clicking spam is like filing a formal complaint at the harbor authority. It updates your personal preferences, enters the official record, and may trigger notification to the shipping company.