What steps should I take when my email campaign experiences block bounces?

Summary

When encountering block bounces, a comprehensive strategy is required. Immediately stop sending emails to mitigate further damage. Diagnose the root cause by examining bounce messages, consulting ESP deliverability teams, and understanding SMTP status codes. Check IP and domain reputation using online tools, looking for blacklisting. Audit email address acquisition practices, focusing on data quality and obtaining explicit consent (double opt-in). Implement or verify email authentication (SPF, DKIM, DMARC). Review email content for spam triggers and warm up new IPs gradually. Clean your email list regularly to remove inactive subscribers. Establish continuous monitoring of domain and IP reputation using tools such as Google Postmaster Tools. Addressing reputation, content, infrastructure, and data quality is paramount to preventing recurrence.

Key findings

  • Immediate Halt: Stopping email sends immediately prevents further damage to sender reputation.
  • Root Cause Diagnosis: Identifying the underlying cause (reputation, content, infrastructure, data) is critical.
  • Reputation Monitoring: Checking IP and domain reputation reveals potential blacklisting issues.
  • Data Quality: Bad data is a significant cause of deliverability problems.
  • Authentication Imperative: SPF, DKIM, and DMARC are essential for verifying email legitimacy.
  • Content Scrutiny: Spam triggers in email content can lead to blocking.
  • Proactive Prevention: Continuous monitoring and preventative measures are crucial to long-term deliverability.

Key considerations

  • ESP Consultation: Engage with your Email Service Provider's deliverability team for support.
  • Acquisition Audit: Review email address acquisition processes for compliance and quality.
  • Authentication Setup: Ensure correct configuration and validation of SPF, DKIM, and DMARC records.
  • List Management: Regularly clean your email list to remove inactive subscribers and bounces.
  • Content Optimization: Review and optimize email content to avoid spam triggers.
  • Reputation Management: Implement strategies to improve and maintain sender reputation.
  • New IP Warmup: Gradually warm up new IP addresses before sending large volumes of email.

What email marketers say
10Marketer opinions

Experiencing block bounces in email campaigns requires a multi-faceted approach focusing on reputation, content, and infrastructure. Immediately check IP and domain reputation for blacklisting. Implement and maintain email authentication (SPF, DKIM, DMARC). Employ list hygiene practices, including removing inactive subscribers and using double opt-in. Review email content for spam triggers and gradually warm up new IPs. Request IP unblocks when appropriate, but avoid repeated self-unblocking. Continuously monitor reputation and address deliverability issues proactively.

Key opinions

  • Reputation Impact: Block bounces often signal sender reputation issues, leading to blacklisting.
  • Authentication is Key: Implementing SPF, DKIM, and DMARC is crucial for verifying email legitimacy.
  • List Hygiene: Maintaining a clean email list improves engagement and reduces bounce rates.
  • Content Matters: Spam trigger words and phrases can lead to emails being flagged and blocked.
  • IP Warm-up: Gradual IP warm-up builds a positive sending reputation with ISPs.
  • Proactive Monitoring: Continuous monitoring of domain and IP reputation identifies potential issues early.

Key considerations

  • Immediate Action: Promptly check IP and domain reputation upon experiencing block bounces.
  • Authentication Setup: Ensure correct configuration of SPF, DKIM, and DMARC records.
  • List Management: Regularly clean your email list to remove inactive subscribers.
  • Content Review: Scrutinize email content for spam trigger words and phrases.
  • New IP Handling: Implement a gradual warm-up strategy for new IP addresses.
  • Reputation Monitoring: Utilize tools like Google Postmaster Tools or Sender Score for continuous reputation tracking.
Marketer view

Marketer from Email Geeks suggests requesting an IP unblock through the provided link, explaining the mistake.

June 2023 - Email Geeks
Marketer view

Email marketer from HubSpot shares that continuously monitor your domain and IP reputation using tools like Google Postmaster Tools or Sender Score to identify and address potential deliverability issues before they result in block bounces.

July 2023 - HubSpot
Marketer view

Email marketer from Email on Acid stresses that implementing email authentication protocols (SPF, DKIM, DMARC) is a critical step to ensure ISPs can verify the legitimacy of your emails, reducing the likelihood of being blocked.

August 2024 - Email on Acid
Marketer view

Email marketer from Litmus explains that certain words and phrases are usually trigger words so always Review email content for spam triggers (e.g., excessive use of promotional language, all caps, or suspicious links) that can cause your emails to be flagged and blocked.

June 2024 - Litmus
Marketer view

Email marketer from Sendinblue shares that maintaining a clean email list and engaging with recipients are crucial steps to improve sender reputation, reduce bounce rates, and avoid being blocked by ISPs.

May 2022 - Sendinblue
Marketer view

Email marketer from Mailjet explains that block bounces often indicate a more significant issue than soft bounces, suggesting problems with sender reputation, IP address blacklisting, or content issues that trigger spam filters.

May 2021 - Mailjet
Marketer view

Email marketer from GMass suggests regularly cleaning your email list by removing inactive subscribers and those who have previously bounced to improve engagement rates and avoid being seen as a spammer.

August 2022 - GMass
Marketer view

Email marketer from Email Marketing Forum advises if you have a new IP address, gradually warm it up by sending emails in increasing volumes over time to build a positive sending reputation with ISPs.

November 2024 - Email Marketing Forum
Marketer view

Email marketer from Campaign Monitor emphasizes that using double opt-in subscription processes ensures recipients have explicitly granted permission to receive emails, reducing the risk of spam complaints and block bounces.

November 2024 - Campaign Monitor
Marketer view

Email marketer from Reddit shares that if you're experiencing block bounces, immediately check your IP address and domain reputation using online tools to identify if you've been blacklisted by any major blocklists.

June 2023 - Reddit

What the experts say
5Expert opinions

When encountering block bounces in email campaigns, experts recommend immediately halting sends to prevent further damage. The initial focus should be on identifying the root cause, which often stems from sender reputation issues, problematic content, infrastructure problems, or bad data within the email list. Examining bounce messages and consulting with your ESP's deliverability team are crucial for gathering clues. Implement corrective measures based on the diagnosis and proactively monitor to prevent future occurrences, focusing on improving data quality and sender reputation.

Key opinions

  • Stop Sending Immediately: Halt email sends upon detecting block bounces to minimize further damage to sender reputation.
  • Identify the Root Cause: Pinpoint the underlying reason for the block bounces, which could be reputation-based, content-related, infrastructure-related, or data-quality-related.
  • Examine Bounce Messages: Carefully analyze rejection messages for specific error codes and clues about the issue.
  • Consult Your ESP: Reach out to your Email Service Provider's deliverability team for guidance and support.
  • Bad Data Causes Issues: Poor quality email data is one of the biggest underlying causes of deliverability issues.

Key considerations

  • Audit Email Acquisition: Review the methods used to acquire email addresses to ensure compliance and quality.
  • Implement Corrective Actions: Take appropriate steps to address the identified cause of the block bounces.
  • Proactive Monitoring: Establish ongoing monitoring processes to detect and prevent future deliverability issues.
  • ESP Communication: Maintain open communication with your ESP to leverage their expertise and resources.
  • Reputation Management: Always be thinking about how to improve and protect your sender reputation
Expert view

Expert from Email Geeks suggests reaching out to ExactTarget/SFMC for advice and to be careful not to repeatedly self-unblock. If issues persist, contact SFMC to check for misconfigurations or dubious content.

December 2023 - Email Geeks
Expert view

Expert from Spam Resource shares that bounces are normally caused by bad data and you should focus on this area to prevent them. Bad data is the cause of many deliverability issues.

July 2023 - Spam Resource
Expert view

Expert from Email Geeks advises to read rejection messages for clues and consult the ESP's deliverability desk.

April 2024 - Email Geeks
Expert view

Expert from Email Geeks advises to stop sending emails, determine the cause and location of the blocks, and audit the email address acquisition process.

October 2022 - Email Geeks
Expert view

Expert from Word to the Wise emphasizes that addressing block bounces requires investigating the cause (reputation, content, infrastructure), implementing corrective actions, and then proactively monitoring to prevent recurrence.

September 2024 - Word to the Wise

What the documentation says
4Technical articles

When facing block bounces, documentation emphasizes understanding bounce types (hard, soft, block) and utilizing bounce notifications to automate list cleaning. Analyzing Non-Delivery Reports (NDRs) for specific error codes and verifying proper email authentication (SPF, DKIM, DMARC) are essential troubleshooting steps. Understanding SMTP enhanced status codes aids in diagnosing the root cause, guiding appropriate remediation and aligning with sending guidelines.

Key findings

  • Bounce Understanding: Knowing the differences between hard, soft, and block bounces is key to diagnosis.
  • Automated List Cleaning: Bounce notifications enable automatic removal of bouncing addresses.
  • NDR Analysis: Non-Delivery Reports contain specific error codes for troubleshooting.
  • Authentication Importance: Correctly configured SPF, DKIM, and DMARC are essential for deliverability.
  • Status Code Significance: SMTP enhanced status codes provide detailed insights into bounce reasons.

Key considerations

  • Notification Setup: Configure bounce notifications within your email sending platform (e.g., Amazon SES).
  • NDR Examination: Regularly review NDRs to identify and address recurring issues.
  • Authentication Verification: Ensure that SPF, DKIM, and DMARC records are correctly configured and validated.
  • Code Interpretation: Learn to interpret SMTP enhanced status codes to understand bounce causes.
  • Guideline Compliance: Align email sending practices with the guidelines of major email providers (e.g., Google).
Technical article

Documentation from AWS explains that using Amazon SES, you can configure bounce notifications to automatically trigger actions such as removing email addresses from your sending list to improve sender reputation and prevent future block bounces.

January 2024 - AWS Documentation
Technical article

Documentation from RFC explains that understanding SMTP enhanced status codes provided in bounce messages helps diagnose the specific reason for the bounce, such as a blocked IP address or policy rejection, and guides appropriate remediation steps.

July 2023 - RFC
Technical article

Documentation from Microsoft details that to troubleshoot block bounces in Exchange Online, review the Non-Delivery Report (NDR) for specific error codes, and check sender authentication settings (SPF, DKIM, DMARC) to ensure they are correctly configured.

March 2022 - Microsoft 365 Documentation
Technical article

Documentation from Google explains that understanding different types of bounces (hard, soft, block) is crucial for diagnosing deliverability issues and adjusting email sending practices accordingly to comply with Google's sending guidelines.

December 2024 - Google Postmaster Tools