What causes high bounce rates on Cyber Monday and how to prevent them?

Summary

High bounce rates on Cyber Monday are primarily caused by poor list hygiene, sending to unengaged recipients, increased spam complaints, and inadequate IP warm-up. Prevention involves meticulous list cleaning (removing invalid and inactive addresses), ensuring permission-based marketing, implementing a sunset policy for inactive subscribers, proper bounce management (distinguishing between hard and soft bounces), gradual IP warm-up, active monitoring of sender reputation and spam complaints, segmenting lists by engagement, and email validation at signup. Analyzing SMTP error codes provides valuable insights for addressing deliverability issues, and holiday email ramp-up should be carefully controlled.

Key findings

  • List Hygiene: Consistent list cleaning and validation are paramount to remove invalid, risky, and unengaged email addresses.
  • Permission-Based Marketing: Obtaining explicit consent ensures that you're only sending to engaged subscribers.
  • IP Warm-up: Gradually increasing sending volume helps establish a positive sending reputation.
  • Segmentation and Sunset Policy: Segmenting lists by engagement and implementing a sunset policy for inactive subscribers improves deliverability.
  • Bounce Management: Differentiating between hard and soft bounces and handling them appropriately is critical for sender reputation.
  • Sender Reputation: Actively monitoring and maintaining a healthy sender reputation is essential for deliverability.
  • Feedback Loops: Establishing feedback loops with ISPs helps identify and remove spam complainers.
  • SMTP Error Codes: Analyzing SMTP error codes provides insights into specific delivery issues.
  • Holiday Email Ramp-Up: Be cautious of email ramp-up over the holidays to minimize the potential triggering of spam filters.

Key considerations

  • Data Validation: Ensure email addresses are validated at signup to prevent bad data from entering your list.
  • List Age: Regularly assess the age and quality of your email list.
  • Bounce Analysis: Analyze bounce codes and responses to understand specific reasons for delivery failures.
  • Stakeholder Education: Communicate the importance of list hygiene and deliverability to stakeholders.
  • Testing and Monitoring: Continuously test and monitor your email program to identify and address deliverability issues.
  • Regular List Cleaning: Implement a consistent schedule for cleaning your email list.
  • Compliance: Ensure you comply with email marketing regulations like GDPR and CAN-SPAM.

What email marketers say
10Marketer opinions

High bounce rates on Cyber Monday are often attributed to a combination of factors, including sending to outdated or unengaged lists, increased spam complaints, hitting spam traps, and failing to warm up IPs properly. Prevention strategies revolve around maintaining good list hygiene through regular cleaning and validation, obtaining explicit consent for email addresses, segmenting lists based on engagement, warming up IPs gradually, and monitoring sender reputation and spam complaints. Email ramp-up over the holidays can also cause bounce rates to increase.

Key opinions

  • List Hygiene: Regular list cleaning (removing hard bounces, suppressing soft bounces) is critical.
  • Permission-Based Marketing: Sending emails only to users who have given explicit consent reduces bounces and complaints.
  • IP Warm-up: Gradually increasing sending volume on Cyber Monday establishes a positive sender reputation.
  • Segmentation: Segmenting lists by engagement (sending to active users first) improves deliverability.
  • Spam Complaints: High spam complaint rates correlate with increased bounce rates and decreased deliverability.
  • Email Ramp-Up: Ramping up the volume of emails over the holidays can cause bounce rates to increase, triggering spam filters

Key considerations

  • Bounce Codes: Analyze bounce codes/responses to understand specific reasons for delivery failures.
  • List Analysis: Analyze email lists for inactive segments (e.g., worst 5%) to justify their inclusion.
  • Stakeholder Communication: Demonstrate the impact of poor list hygiene to stakeholders using data and examples.
  • Email Validation: Implement validation at signup to prevent bad addresses from entering the list.
  • Ramp-Up Consideration: Be careful of email ramp-up over the holidays to minimise the potential triggering of spam filters.
Marketer view

Email marketer from Campaign Monitor advises monitoring spam complaints. High spam complaint rates directly correlate with higher bounce rates and lower deliverability.

December 2024 - Campaign Monitor
Marketer view

Email marketer from Reddit shares that regular list cleaning is paramount. Remove hard bounces immediately and suppress serial soft bouncers after a few attempts.

December 2024 - Reddit
Marketer view

Email marketer from EmailToolTester emphasizes the need for permission-based marketing. Sending to purchased lists or contacts without explicit consent significantly increases bounce rates and spam complaints.

August 2023 - EmailToolTester
Marketer view

Email marketer from Litmus recommends validating email addresses at the point of entry (e.g., signup forms) to prevent invalid addresses from entering your list.

February 2022 - Litmus
Marketer view

Marketer from Email Geeks (Michelle) confirms that the email ramp-up during the holidays likely triggered spam filters. Marketer from Email Geeks (Steve) advises splitting the list into segments based on engagement to prioritize sends and analyse the 'worst 5%' segment to demonstrate issues to stakeholders.

April 2022 - Email Geeks
Marketer view

Marketer from Email Geeks suggests checking bounce codes/responses and if anything different was done. He refers to AT&T support for basics and advises analysing the list for inactive segments, especially the worst 5%, to justify its inclusion. He suspects the Black Friday period's busyness may have led to arbitrary spam decisions. Finally if deliverability returns to normal, continue the data analysis.

March 2024 - Email Geeks
Marketer view

Email marketer from Mailjet Blog explains that high bounce rates during Cyber Monday can stem from sending to outdated lists, increased spam complaints, or hitting spam traps. They recommend cleaning your list, warming up IPs, and segmenting sends.

March 2025 - Mailjet Blog
Marketer view

Email marketer from ZeroBounce explains that regularly using an email validation service to identify and remove invalid, risky, and inactive email addresses before sending helps maintain a clean list and reduces bounce rates.

February 2022 - ZeroBounce
Marketer view

Email marketer from Email Marketing Forum explains that during Cyber Monday, you should ensure your IP address is properly warmed up, gradually increasing sending volume to establish a positive sending reputation.

January 2022 - Email Marketing Forum
Marketer view

Email marketer from HubSpot Blog suggests segmenting your list based on engagement. Send to your most active subscribers first to improve deliverability and reduce bounce rates.

September 2024 - HubSpot Blog

What the experts say
4Expert opinions

High bounce rates, especially on events like Cyber Monday, are significantly influenced by list hygiene and bounce management practices. Maintaining a clean and validated email list is critical; this includes immediate removal of hard bounces and careful handling of soft bounces. Additionally, implementing a sunset policy to remove inactive subscribers helps prevent deliverability issues. Consistently exceeding a 2% bounce rate indicates potential issues with email marketing practices.

Key opinions

  • Bounce Management: Proper handling of hard and soft bounces is crucial for maintaining sender reputation.
  • List Hygiene: Poor list hygiene, including old or unvalidated email addresses, significantly impacts bounce rates.
  • Sunset Policy: Implementing a sunset policy for inactive subscribers reduces bounce rates and spam complaints.
  • High Bounce Rate Indicator: A bounce rate exceeding 2% suggests underlying issues with email marketing practices.

Key considerations

  • Data Validation: Ensure email addresses are validated to avoid deliverability problems.
  • List Age: Be mindful of the age of your email list, as older lists often contain invalid addresses.
  • Permission Practices: Verify that email addresses were obtained with proper permission to avoid deliverability issues.
  • Third-Party Review: Consider using third-party services to review and clean your email data.
Expert view

Expert from Word to the Wise recommends implementing a sunset policy to remove inactive subscribers. Sending to unengaged recipients lowers engagement metrics and increases the risk of bounces and spam complaints.

March 2024 - Word to the Wise
Expert view

Expert from Spam Resource explains that careful bounce management is crucial for maintainability. It's important to distinguish between hard and soft bounces. Hard bounces should be removed immediately, while soft bounces should be retried a few times before removal. Proper bounce handling is vital for sender reputation.

April 2021 - Spam Resource
Expert view

Expert from Spam Resource explains that one major cause of deliverability issues that impact bounce rates is poor list hygiene. This comes down to bad data, where data has not been validated or email addresses are old.

January 2023 - Spam Resource
Expert view

Expert from Word to the Wise explains that if you’re experiencing high bounce rates (higher than 2%), it might be a sign that you’re not following best practices and should review what is happening. Some things to check are if the list is old, was it permission passed etc. You can also use a 3rd party service to review data.

January 2024 - Word to the Wise

What the documentation says
5Technical articles

High bounce rates are influenced by deliverability failures, often rooted in issues addressed by email service providers' (ESPs) documentation. Understanding the difference between hard and soft bounces is essential for list management. Analyzing SMTP error codes provides specific insights into bounce reasons. Maintaining a strong sender reputation, as monitored through tools like Google Postmaster Tools, is critical. Regularly cleaning email lists, removing inactive subscribers, and setting up feedback loops with ISPs further enhances deliverability by addressing spam complaints and engagement metrics.

Key findings

  • Bounce Types: Differentiating between hard (permanent) and soft (temporary) bounces is crucial for list hygiene.
  • SMTP Error Codes: Analyzing SMTP error codes helps pinpoint specific reasons for email delivery failures.
  • Sender Reputation: A strong sender reputation is essential for good deliverability and reduced bounce rates.
  • List Cleaning: Regular list cleaning and removing inactive subscribers improves engagement and sender reputation.
  • Feedback Loops: Setting up feedback loops with ISPs helps identify and remove spam complainers, improving deliverability.

Key considerations

  • Hard vs Soft Bounces: Implement processes for managing hard bounces separately from soft bounces.
  • Error Code Analysis: Establish a system for regularly reviewing SMTP error codes to identify recurring issues.
  • Postmaster Tools: Actively monitor sender reputation using tools like Google Postmaster Tools.
  • Engagement Metrics: Focus on improving engagement metrics to demonstrate the value of your email program to ISPs.
  • ISP Relationships: Proactively work with ISPs through feedback loops to resolve deliverability issues and minimize bounces.
Technical article

Documentation from SendGrid explains that hard bounces typically indicate permanent delivery failures (invalid email address), while soft bounces are temporary issues (full mailbox). Understanding these distinctions is crucial for list hygiene.

March 2024 - SendGrid Documentation
Technical article

Documentation from Google explains that sender reputation is crucial for deliverability. Monitor your reputation in Google Postmaster Tools to identify and address potential issues.

October 2022 - Google
Technical article

Documentation from Mailchimp explains that regularly cleaning your email list and removing inactive subscribers improves engagement metrics and helps maintain a healthy sender reputation, which reduces bounce rates.

May 2024 - Mailchimp
Technical article

Documentation from RFC Editor details SMTP error codes, which provide insights into the reason for bounces. Analyzing these codes helps diagnose and address specific delivery issues.

May 2023 - RFC Editor
Technical article

Documentation from SparkPost states that setting up feedback loops with major ISPs helps you identify and remove subscribers who mark your emails as spam, which improves deliverability and reduces bounce rates.

October 2023 - SparkPost