What causes high spam complaint rates in Gmail, and how can they be fixed?

Summary

High spam complaint rates in Gmail stem from a multitude of interconnected factors related to sender practices, list management, and recipient perception. These include sending unsolicited or irrelevant content, using outdated or purchased lists, lacking explicit consent (particularly from lead magnets), excessively high sending frequency, unclear unsubscribe processes, and poor email authentication. Senders are often penalized when recipients forget subscribing, are added to lists without permission ('list bombing'), or encounter spam traps. Conversely, low email engagement directly correlates with high complaint rates. Effective mitigation requires a multifaceted approach: enhancing list hygiene through double opt-in and regular cleaning, improving content segmentation and personalization, carefully managing send frequency, simplifying unsubscription procedures, implementing robust email authentication protocols (SPF, DKIM, DMARC), actively monitoring feedback loops, respecting recipient preferences, and leveraging Complaint Feedback Loops (FBLs) for prompt issue resolution. Critically, continuing to email recipients who have unsubscribed is not only detrimental but also illegal, underscoring the importance of respecting user autonomy.

Key findings

  • Recipient Engagement Crucial: Recipients actively marking emails as spam indicates a fundamental disconnect between sender intent and recipient expectation, highlighting the necessity of understanding and addressing user preferences.
  • Legal & Ethical Imperative: Mailing unsubscribed recipients is illegal and unethical, demanding strict adherence to opt-out requests and privacy regulations.
  • Lead Magnet Caveats: Acquiring subscribers through lead magnets alone can lead to high spam complaints if follow-up content doesn't align with initial expectations or provides sustained value.
  • Authentication a Must: Lack of email authentication (SPF, DKIM, DMARC) significantly increases the likelihood of emails being flagged as spam, emphasizing the importance of technical configuration for deliverability.
  • List Management Central: Proactive list management, including double opt-in, regular cleaning, and avoidance of purchased lists, is foundational to minimizing spam complaints.
  • Comprehensive Feedback Loop: Actively monitoring and responding to feedback loops, including spam complaints and unsubscribe requests, is crucial for continuous improvement and adaptation of email marketing strategies.

Key considerations

  • Prioritize User Autonomy: Empower recipients with clear and easily accessible options for managing their email preferences, fostering trust and reducing instances of spam complaints.
  • Content Relevance is Key: Continuously evaluate and refine content strategies to ensure alignment with subscriber interests, fostering engagement and minimizing irrelevant messaging that triggers spam complaints.
  • Optimize Sending Practices: Carefully manage sending frequency and volume to avoid overwhelming subscribers, balancing outreach with respect for their time and attention.
  • Technical Infrastructure Investments: Invest in and maintain robust email authentication protocols (SPF, DKIM, DMARC) to establish sender credibility and improve deliverability rates.
  • Continuous Improvement Mindset: Adopt a data-driven approach to email marketing, continuously analyzing performance metrics and iteratively improving strategies based on user feedback and evolving best practices.

What email marketers say
8Marketer opinions

High spam complaint rates in Gmail stem from various factors related to sender practices and recipient perception. Sending irrelevant content, using outdated lists, lacking proper consent (especially with lead magnets), high sending frequency, and misleading subject lines are significant contributors. Furthermore, recipients forgetting their subscriptions, being added without permission (list bombing), or facing difficulties unsubscribing exacerbate the problem. Solutions involve improving email list hygiene, implementing double opt-in, segmenting and personalizing content, respecting send frequency, simplifying unsubscription, improving email engagement rates, and authenticating email senders.

Key opinions

  • Irrelevant Content: Sending emails with content that isn't relevant to subscribers significantly increases spam complaints.
  • Consent Issues: Failing to obtain proper consent, especially when using lead magnets, leads to high complaint rates.
  • List Hygiene: Outdated and uncleaned email lists are a major source of spam complaints.
  • Sending Frequency: Sending emails too frequently annoys subscribers and drives up complaint rates.
  • Unsubscribe Issues: Difficult or unclear unsubscription processes contribute to spam complaints.
  • Engagement Impact: Poor email engagement is directly correlated with higher spam complaint rates.
  • List Bombing: Adding users to a list without their permission leads to high spam complaints.

Key considerations

  • Segmentation & Personalization: Improve email segmentation and personalization to deliver relevant content and increase engagement.
  • Double Opt-in: Implement double opt-in to ensure subscribers genuinely want to receive emails and reduce spam complaints.
  • List Cleaning: Regularly clean email lists to remove inactive or unengaged subscribers.
  • Frequency Management: Carefully manage sending frequency based on subscriber preferences and test different schedules to find the optimal balance.
  • Unsubscribe Process: Make the unsubscribe process clear, easy, and immediate to respect subscriber preferences.
  • Engagement Strategies: Implement strategies to improve email engagement, such as targeted content and A/B testing.
Marketer view

Email marketer from Twilio SendGrid reports that improving email engagement rates is the best way to reduce spam complaints. They said to segment your lists based on subscriber activity, send targeted content, and use A/B testing to optimize subject lines and email copy.

November 2021 - Twilio SendGrid
Marketer view

Email marketer from Mailjet shares that irrelevant content, sending too frequently, and not providing an easy way to unsubscribe all contribute to spam complaints. Fixes include sending targeted content, respecting send frequency, and making the unsubscribe process clear and accessible.

October 2024 - Mailjet
Marketer view

Marketer from Email Geeks shares that users who sign up for lead magnets, such as '20% off', will likely mark repeat emails as spam.

December 2023 - Email Geeks
Marketer view

Email marketer from Reddit shares that a common cause of spam complaints is that users forget they subscribed. Reminding users how they signed up, offering preference updates, and honoring unsubscription requests immediately can help reduce complaints.

August 2023 - Reddit
Marketer view

Email marketer from Email Marketing Forum suggests that sending emails too frequently causes user annoyance and results in spam complaints. They said to implement a reasonable sending schedule, based on user preferences, and to test sending frequency to find the optimal balance.

March 2022 - Email Marketing Forum
Marketer view

Email marketer from Neil Patel shares that high spam complaint rates are caused by sending irrelevant content to subscribers. Fixes include improving segmentation and personalization to ensure subscribers receive content they find valuable.

January 2022 - Neil Patel
Marketer view

Email marketer from HubSpot explains that spam complaints arise from sending emails to outdated lists, not obtaining proper consent, or having misleading subject lines. They say that to fix this, regularly clean email lists, get explicit opt-in, and ensure the subject line accurately reflects the email's content.

October 2023 - HubSpot
Marketer view

Email marketer from Litmus discusses "list bombing" a practice where companies add users to a list without their permission. They share the importance of using double opt-in to verify email addresses and ensure subscribers genuinely want to receive communications.

October 2023 - Litmus

What the experts say
5Expert opinions

High spam complaint rates in Gmail indicate recipients are actively marking emails as spam, a problem not solvable through technical means alone. Continuing to email unsubscribed recipients is illegal. Effective spam complaint management relies on maintaining high list quality through double opt-in and regular cleaning, properly handling unsubscribe requests by making them easy and immediate, and utilizing Complaint Feedback Loops (FBLs) to identify and remove problem addresses.

Key opinions

  • Recipient Action: High spam complaint rates are a direct result of recipients actively marking emails as spam.
  • Legality of Unsubscribes: It is illegal to continue emailing recipients who have unsubscribed.
  • Importance of List Quality: Maintaining a high-quality email list is crucial for minimizing spam complaints.
  • Effective Unsubscribes: Properly handling unsubscribe requests is essential for reducing spam complaints.
  • FBL Utilization: Complaint Feedback Loops (FBLs) help identify and remove users who mark emails as spam.

Key considerations

  • Focus on Recipient Preference: Prioritize recipient preferences and ensure they genuinely want to receive emails.
  • Legal Compliance: Strictly adhere to legal requirements regarding unsubscribes and email marketing practices.
  • Proactive List Management: Implement proactive list management strategies, including double opt-in and regular list cleaning.
  • Easy Unsubscribe Process: Provide a straightforward and immediate unsubscribe process to respect recipient choices.
  • FBL Implementation: Utilize Complaint Feedback Loops to continuously monitor and improve email sending practices.
Expert view

Expert from Email Geeks states that if recipients have unsubscribed and you continue to mail them, you are breaking the law in the US.

August 2021 - Email Geeks
Expert view

Expert from Email Geeks explains that the high spam complaint rate (7%) indicates recipients are actively marking emails as spam within their email clients. The expert emphasizes that you can't technically solve the problem of people not wanting your emails and that continually mailing recipients who don't want your emails will result in delivery issues.

December 2023 - Email Geeks
Expert view

Expert from Word to the Wise shares that properly handling unsubscribe requests is essential to reducing spam complaints. They suggest providing a clear and easy way to unsubscribe, and immediately removing unsubscribed users from the mailing list to respect their preferences and avoid further complaints.

May 2024 - Word to the Wise
Expert view

Expert from Word to the Wise emphasizes that list quality is paramount to avoid spam complaints. Using double opt-in, cleaning inactive subscribers, and avoiding purchased lists are crucial to maintaining a healthy, engaged audience.

August 2024 - Word to the Wise
Expert view

Expert from Spam Resource explains that Complaint Feedback Loops (FBLs) from ISPs and ESPs help identify and remove users who mark emails as spam. Proper FBL implementation and monitoring helps reduce spam complaints by identifying problem addresses.

November 2024 - Spam Resource

What the documentation says
5Technical articles

High spam complaint rates in Gmail are attributed to factors such as unsolicited emails, lack of proper email authentication (SPF, DKIM, DMARC), sudden volume spikes, and sending to spam traps. These issues damage sender reputation and lead to deliverability problems. Solutions include email authentication, adherence to sending limits, monitoring feedback loops, promptly removing complainers, implementing list hygiene, obtaining explicit consent, clear unsubscribe options, relevant content, and avoiding purchased lists.

Key findings

  • Unsolicited Mail: Sending unsolicited emails is a major driver of spam complaints.
  • Authentication Failure: Lack of proper email authentication (SPF, DKIM, DMARC) increases spam rates.
  • Volume Spikes: Sudden increases in email volume can trigger spam filters and complaints.
  • Spam Traps: Sending emails to spam traps significantly harms sender reputation.
  • Reputation Damage: Spam complaints directly damage sender reputation, leading to deliverability issues.

Key considerations

  • Email Authentication: Implement SPF, DKIM, and DMARC to authenticate emails and improve deliverability.
  • Sending Limits: Adhere to recommended sending limits to avoid triggering spam filters.
  • Feedback Loop Monitoring: Monitor feedback loops to identify and address spam complaints promptly.
  • List Hygiene Practices: Implement best practices for list hygiene, including double opt-in and regular cleaning.
  • Consent & Relevance: Obtain explicit consent from recipients and ensure content is relevant to their interests.
Technical article

Documentation from Google Support explains that high spam rates in Gmail are influenced by factors such as sending unsolicited mail, lack of proper authentication, and sudden spikes in email volume. To fix it, they advise authenticating emails with SPF, DKIM, and DMARC, adhering to recommended sending limits, and monitoring feedback loops.

July 2021 - Google Support
Technical article

Documentation from DMARC.org shares that not authenticating your emails using SPF, DKIM, and DMARC can lead to deliverability problems and increased spam complaints. Implement email authentication protocols to verify the sender's identity and protect against phishing and spoofing.

March 2021 - DMARC.org
Technical article

Documentation from Microsoft explains that spam complaints are a key factor in determining whether an email lands in the junk folder. Microsoft advises that to minimize spam complaints, you should obtain explicit consent from recipients, provide clear instructions on how to unsubscribe, and ensure content is relevant to the subscriber's interests.

August 2021 - Microsoft
Technical article

Documentation from Validity says that spam complaints directly damage sender reputation, leading to deliverability issues. To mitigate this, the documentation says to monitor sender reputation metrics, promptly remove complainers from your list, and implement best practices for list hygiene.

August 2022 - Validity
Technical article

Documentation from Spamhaus explains that sending emails to spam traps (email addresses used to identify spammers) increases spam complaint rates and damages sender reputation. They share that to avoid spam traps, use double opt-in, regularly clean email lists, and avoid purchasing email lists.

December 2024 - Spamhaus