How do I detect spam complaints?

Detecting spam complaints depends on what email service or mail infrastructure you use, but the general approaches are:

1) Check feedback loops / complaint webhooks

If you send mail through a provider like SendGrid, Mailgun, Amazon SES, Postmark, etc., they often provide:

• Spam complaint events
• Feedback loop notifications
• Webhook callbacks

You can subscribe to those events and log when recipients mark your email as spam.

2) Monitor bounce/complaint reporting in your ESP

Most email service providers expose dashboards or APIs with metrics like:

• Spam complaints
• Hard bounces
• Unsubscribes
• Delivery rate

Examples:

• Amazon SES: Complaint notifications via SNS
• SendGrid: Event Webhook with spamreport
• Mailgun: Webhooks for complained events
• Postmark: Spam complaint webhooks

3) Use ISP feedback loops

Some mailbox providers offer complaint feedback loops, though availability varies:

• Yahoo
• AOL
• Microsoft
• Comcast
• Others depending on region/provider

These send complaint signals to your mail system when a user marks your message as spam.

4) Detect indirect signs in your own analytics

You usually can’t see every spam complaint directly, but you can watch for patterns like:

• Sudden drop in open rates
• Increased unsubscribe rate
• More emails landing in spam
• Higher bounce rates
• Low engagement from certain segments

5) If you run your own mail server

You can detect complaints only if:

• A feedback loop is configured
• Your ISP/relay provider forwards complaint reports
• You receive abuse reports at abuse@yourdomain.com or similar

Without provider support, you generally cannot directly know if a recipient clicked “Report spam.”

Practical recommendation

Set up:

1. Complaint webhooks from your ESP
2. Bounce/unsubscribe tracking
3. Automated suppression of complaint addresses
4. Alerts if complaint rate exceeds a threshold, e.g. 0.1%–0.3%

If you tell me which provider you use, I can show the exact way to detect spam complaints for that platform.