Summary
Across various sources, a consensus emerges that a spam rate exceeding 0.1% is generally considered high and detrimental to email deliverability. However, some sources advise aiming for rates below 0.05% or even 0.02%. ActiveCampaign indicates a threshold of 0.3%, while EmailGeeks Forum suggests 0.5% as a critical point. Hotmail may block around 0.2%. It's essential to calculate complaint rates as complaints received divided by delivered messages, not total sends. User actions significantly influence filtering, and high spam rates impact sender reputation, potentially leading to blacklisting. Some ESPs action single complaints. The calculation is also skewed due to FBLs not being sent if mail lands in the bulk folder. Monitoring feedback loops, maintaining list hygiene, and understanding spam filter mechanisms are crucial for mitigating risks.
Key findings
- Spam Rate Threshold: A spam rate above 0.1% is generally considered high and can lead to deliverability issues.
- Complaint Calculation: Complaint rates should be calculated based on delivered messages (to inbox), not total sends.
- Varying ESP Policies: Specific thresholds for blocking or filtering can vary across different ESPs, with some taking action based on a single complaint.
- Sender Reputation Impact: High spam rates negatively impact sender reputation and can lead to blacklisting.
- User Actions Matter: User actions (e.g., marking emails as spam) play a significant role in determining deliverability.
Key considerations
- Monitor and Respond: Regularly monitor spam complaint rates and take immediate action to address any spikes.
- List Hygiene: Implement and maintain robust list hygiene practices, including segmentation, permission-based sending, and easy unsubscribe options.
- Feedback Loops: Actively monitor and utilize feedback loops to identify and resolve deliverability problems.
- Spam Filter Awareness: Develop a comprehensive understanding of how spam filters work to optimize sending practices.
- Actionable Data: Consider the FBL limitations and the skewed calculations.
- Data Privacy: Be aware that B2B senders might not have FBLs, impacting complaint rate calculations.
What email marketers say
13 marketer opinions
A high spam rate, which can lead to ESP blocking, is generally considered to be above 0.1%. However, some sources indicate that rates as low as 0.02% should be aimed for, while others suggest that exceeding 0.3% or even 0.5% is critical. Complaint rates should be calculated as complaints received divided by emails sent to domains supporting feedback loops, rather than total emails sent, to avoid underreporting. Maintaining a good sender reputation through list segmentation, permission-based sending, easy unsubscribe options, and monitoring feedback loops is crucial for avoiding deliverability issues.
Key opinions
- Spam Rate Threshold: Most sources agree that a spam rate exceeding 0.1% is problematic and can lead to blocking or deliverability issues.
- Complaint Rate Calculation: Complaint rates should be calculated based on emails sent to domains with feedback loops, not total emails sent.
- Hotmail Blocking: Hotmail may block senders with a spam rate around 0.2%.
- Aggressive Threshold: Some ESPs may take action for a single complaint, regardless of percentage.
- Differing Rates: The point in which you will be blocked differs between ESPs.
Key considerations
- Monitor Feedback Loops: Regularly monitor feedback loops to identify and address deliverability issues promptly.
- List Hygiene: Maintain good list hygiene practices, including list segmentation, permission-based sending, and easy unsubscribe options.
- Sender Reputation: Prioritize building and maintaining a positive sender reputation through responsible sending practices.
- Multiple Metrics: A single metric in isolation is not perfect - how they relate to one another tells a story.
- Bulk folder consideration: FBLs aren’t sent if mail goes into the bulk folder, so your calculation of FBL rate is going to be off because you’re using the sent rate not the inbox rate.
Marketer view
Email marketer from Mailjet's Blog explains that anything above a 0.1% spam complaint rate is considered high and can lead to deliverability issues, including potential blocking by ESPs. They emphasize monitoring feedback loops to address deliverability issues promptly.
26 Nov 2024 - Mailjet's Blog
Marketer view
Email marketer from HubSpot suggests aiming for a spam complaint rate below 0.05% to maintain a good sender reputation. They stress the importance of list segmentation, permission-based sending, and providing easy unsubscribe options to keep complaint rates low.
5 Nov 2023 - HubSpot
What the experts say
5 expert opinions
Experts emphasize the importance of accurate complaint rate calculation, focusing on user actions and the number of delivered messages rather than total sends. They highlight that spam filters are heavily influenced by user complaints, impacting sender reputation and deliverability. Also even calculating the FBL (feedback loop) rate based on emails sent to domains that support FBLs can be wrong because FBLs aren’t sent if mail goes into the bulk folder, so the calculation will be off because you’re using the sent rate, not the inbox rate, and finally that ESPs will action a single complaint.
Key opinions
- Complaint Calculation: Complaint rates should be calculated by dividing the number of complaints by the number of delivered messages.
- User Actions Matter: User actions, such as marking emails as spam, significantly influence spam filtering and sender reputation.
- FBL Limitations: Calculating FBL rate can be skewed because FBLs aren't sent if mail lands in the bulk folder.
- Single Complaints: ESPs can take action based on a single complaint.
Key considerations
- Analyze Abuse Reports: Carefully analyze the reasons behind user 'abuse' reports to understand and address the root causes of complaints.
- Understand Spam Filters: Gain a thorough understanding of how spam filters work to optimize sending practices and improve deliverability.
- Data Accuracy: Ensure accuracy in data and consider deliverability to inboxes versus 'sent' volume.
- ESPs Vary: Compliance actions vary between ESPs, with some acting on single complaints.
- B2B Considerations: Be aware that B2B senders might not have FBLs, impacting complaint rate calculations.
Expert view
Expert from Email Geeks clarifies the question is about ESPs and highlights compliance actions may happen for a single complaint and points out the importance of calculating complaint percentages correctly and that some senders (B2B) may not have FBLs.
29 Nov 2024 - Email Geeks
Expert view
Expert from Word to the Wise Editorial Team, indicates the importance of understanding how spam filters work. While not directly specifying a rate, they emphasize the role of user complaints in triggering filters and damaging sender reputation. They underscore that excessive complaints will lead to deliverability issues and the importance of consent and relevant content.
30 Aug 2024 - Word to the Wise
What the documentation says
4 technical articles
Documentation emphasizes that a spam complaint rate exceeding 0.1% negatively impacts sender reputation and deliverability. High spam rates, especially as reported by users, can lead to filtering or blocking. Complaint rates should be calculated based on delivered messages, not total sends. Regularly monitoring spam rates and addressing spikes through improved sending practices and list hygiene are crucial.
Key findings
- Complaint Rate Threshold: A spam complaint rate above 0.1% is considered problematic by most sources.
- Calculation Method: Complaint rates must be calculated based on the number of delivered messages (to the inbox), not total sends.
- Sender Reputation: High spam complaint rates damage sender reputation, potentially leading to blacklisting.
- Gmail Impact: High spam rates severely affect deliverability to Gmail users.
Key considerations
- Regular Monitoring: Regularly monitor spam rates using tools like Google Postmaster Tools and Microsoft SNDS.
- Address Spikes: Take immediate action to address any spikes in spam rates by reviewing sending practices and list hygiene.
- Healthy Deliverability: Maintain a spam rate below 0.1% for healthy email deliverability.
- Reputation Management: Proactively manage sender reputation through responsible email marketing practices.
Technical article
Documentation from SendGrid indicates that a spam complaint rate above 0.1% is problematic and can negatively impact your sender reputation. They advise that maintaining a rate below 0.1% is crucial for healthy email deliverability and they also advise that you should calculate your complaint rate as a percentage of delivered messages.
12 Jul 2023 - SendGrid
Technical article
Documentation from Microsoft SNDS describes that complaint rates should be calculated by dividing the number of complaints by the number of emails delivered to the inbox (not total sends). They also outline that a significant percentage of spam complaints can result in filtering or blocking of future emails.
14 Sep 2023 - Microsoft SNDS
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