Complain Rate

What is it?

What is it?

The "Complaint Rate" in email marketing is a metric that measures the percentage of recipients who mark an email as spam or junk against the total number of emails delivered. It is a critical indicator of how recipients perceive the relevance and value of the emails they receive. A high complaint rate can negatively impact a sender's reputation with Internet Service Providers (ISPs) and Email Service Providers (ESPs), potentially leading to deliverability issues or even blacklisting.

Key points to remember

Key points to remember

  • Indicator of Subscriber Satisfaction: A low complaint rate suggests that content is well-received and considered valuable by recipients, whereas a high rate indicates dissatisfaction.

  • Impacts Deliverability: ISPs and ESPs monitor complaint rates closely. Exceeding thresholds, even minimally, can affect email deliverability.


  • Feedback Mechanism: Complaint rates serve as direct feedback from your audience, signaling when it's time to reassess content, frequency, and targeting strategies.


  • Preventive Measures: Regular list cleaning, proper segmentation, transparent opt-in processes, and easy unsubscribe options can help minimize complaint rates.


  • Benchmarking: It's important to benchmark complaint rates against industry averages to understand how your emails compare to others in your sector.

Example of Use

Example of Use

Content Strategy Adjustment: After noticing an uptick in the complaint rate, a newsletter publisher revises their content strategy to focus more on topics that resonate with their audience based on past engagement metrics.

Opt-In Confirmation: A retail brand implements a double opt-in process for new subscribers, significantly reducing their complaints by ensuring recipients genuinely want to receive their emails.

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