When sending emails to subscribers, it’s important to send to people that actually want to receive your newsletter. When receiving unsolicited email, users can delete the email, click on the ‘Report this email as Spam’ link or click on ‘Mark this as Junk’ in their email client.

When email is marked as spam in webmail clients, like Hotmail and Yahoo, a Feedback Loop (FBL) tracks the users who have performed this action. Email reports count FBLs as complaints, which is recorded in the more detailed Contact Activity section of the email recipients report.