Documentation

Spam complaints.

A complaint is a recipient telling their mailbox provider that your message was spam. It is the strongest negative signal a sender can get.

What a complaint is

When a recipient presses “Report spam” or “This is junk”, some mailbox providers send a report back to the sender through a feedback loop. Mailtruss records it as a complained event on the message and sends the email.complained webhook. The message's status shows Complained, with the diagnosis “Recipient marked the message as spam”.

What Mailtruss does

The address is added to your suppression list, and complaints are kept there permanently. Later sends to that address are skipped. This protects you: mailing someone who complained makes the next complaint more likely, and providers weigh complaints heavily.

What you should do

Never email this recipient again. A retry is not safe and is not offered.
Review how consent was collected for the list this person was on. Mail people only when they asked for it.
Make unsubscribing easy. Broadcasts carry an unsubscribe link and a one-click List-Unsubscribe header automatically; for other mail, add a link and use topics so people can pick what they receive instead of reporting you.
Watch the rate, not single reports. Mailtruss alerts you as complaints rise and acts on them at fixed levels, which are published in the acceptable use policy.

Try it without sending real mail

In test mode, send to complained@mailtruss.test to see what a complaint event looks like.