How do email experts troubleshoot customer deliverability issues?

Summary

Email experts address customer deliverability issues through a multifaceted approach. Foundational steps include ensuring proper email authentication (SPF, DKIM, DMARC), closely monitoring sender reputation via bounce rates, complaints, and engagement, and adhering to bulk sender guidelines provided by mailbox providers like Gmail and Microsoft. Maintaining list hygiene through regular cleaning and implementing double opt-in processes is also critical. Additional strategies involve optimizing email content to avoid spam triggers, ensuring proper email design and HTML, setting up feedback loops with ISPs, and adjusting sending volume through throttling. Some troubleshooting involves investigating customer-specific issues or acknowledging that certain deliverability problems fall outside their area of expertise.

Key findings

  • Authentication: Proper email authentication (SPF, DKIM, DMARC) is critical for ensuring deliverability and preventing spoofing.
  • Reputation Monitoring: Monitoring IP and domain reputation, as well as sender reputation metrics, helps diagnose and address deliverability problems.
  • List Hygiene: Maintaining a clean and engaged email list significantly improves deliverability rates.
  • Content Optimization: Optimizing email content to avoid spam triggers and ensuring clean HTML code are essential.
  • Feedback Loops: Setting up feedback loops with ISPs provides valuable data on spam complaints.
  • Throttling: Adjusting sending volume through throttling can prevent spam filters from being triggered.

Key considerations

  • Sender Guidelines: Adhere to bulk sender guidelines provided by major mailbox providers.
  • Customer Specific Issues: Investigate customer-specific issues to identify the source of the problem.
  • Blacklist Checks: Regularly check IP addresses and domains against blacklists.
  • Engagement Analysis: Monitor engagement metrics to identify subscribers who are not interacting with emails.
  • Email Design and Rendering: Ensure emails are designed to render correctly across various email clients and devices.
  • Scope of Expertise: Understand the limits of one's expertise when it comes to individual deliverability problems.

What email marketers say
10Marketer opinions

Email experts troubleshoot customer deliverability issues by addressing various factors. These include investigating customer-specific problems, like those stemming from URLs, ensuring proper email authentication (SPF, DKIM, DMARC), monitoring IP and domain reputation through blocklist checks, and maintaining a clean email list. Strategies also involve optimizing email content to avoid spam trigger words and ensuring proper email design and HTML. Additionally, monitoring sender reputation metrics, such as bounce rates and engagement, and adjusting sending volume through throttling are vital.

Key opinions

  • Authentication: Proper email authentication (SPF, DKIM, DMARC) is critical for deliverability.
  • Reputation Monitoring: Monitoring IP and domain reputation helps diagnose deliverability issues.
  • List Hygiene: Maintaining a clean email list improves deliverability.
  • Content Optimization: Avoiding spam trigger words and optimizing email design are important.
  • Sender Reputation: Monitoring sender reputation metrics helps identify deliverability problems.
  • Throttling: Adjusting sending volume can prevent spam filters from being triggered.

Key considerations

  • Customer Issues: Investigate specific customer-related issues, such as problems with URLs in their emails.
  • Blacklist Checks: Regularly check IP and domain against blacklists to avoid delivery problems.
  • Engagement Metrics: Monitor engagement metrics to identify issues and adjust strategies accordingly.
  • Email Design: Ensure proper email design and HTML to improve rendering and avoid spam filters.
  • Double Opt-in: Use double opt-in to ensure subscribers are genuinely interested in receiving emails.
Marketer view

Email marketer from Mailjet shares that monitoring your sending IP's reputation is crucial for diagnosing deliverability problems; low reputation scores with blocklists will cause delivery issues, and proactively monitoring and maintaining a positive reputation is key.

August 2024 - Mailjet
Marketer view

Email marketer from Email on Acid explains that maintaining a clean email list is important. Regularly remove inactive subscribers and those who have unsubscribed. Use double opt-in to ensure subscribers are genuinely interested in receiving emails.

October 2023 - Email on Acid
Marketer view

Email marketer from SendGrid shares that proper email authentication (SPF, DKIM, DMARC) is critical to ensure mailbox providers trust the sender and deliver emails to the inbox. Failure to authenticate can result in emails being marked as spam or blocked.

August 2021 - SendGrid
Marketer view

Email marketer from Email Geeks shares their experience of dealing with a customer service issue where a customer claimed not to receive mail, and after investigation, it was confirmed that the issue was on the customer's end.

April 2024 - Email Geeks
Marketer view

Email marketer from Email Geeks shares an experience where a client was having deliverability issues due to a URL in their content, and after confirming with the provider, it was determined that the URL was indeed the problem.

March 2025 - Email Geeks
Marketer view

Email marketer from GlockApps shares that avoiding spam trigger words in your email subject line and body can significantly improve deliverability. These words often flag your email as spam. Use a spam checker tool to find these words.

February 2022 - GlockApps
Marketer view

Email marketer from StackOverflow explains that monitor your sender reputation by tracking bounce rates, spam complaints, and unsubscribe rates, as well as engagement metrics such as open rates and click-through rates. Low engagement can signal deliverability problems.

January 2024 - StackOverflow
Marketer view

Email marketer from Reddit explains that to troubleshoot deliverability, it's important to check if your sending IP or domain is blacklisted. Many free tools are available online to check your status against common blacklists. If you are blacklisted you need to contact the blacklist to get delisted.

April 2024 - Reddit
Marketer view

Email marketer from Litmus explains that faulty HTML and poor email design can affect deliverability. Use responsive design and test email rendering across different email clients. Also ensure your code is clean and follows best practices.

March 2022 - Litmus
Marketer view

Email marketer from Gmass explains that throttling back the number of emails you send within a certain time period can help to address deliverability issues. Sending too many emails in a short space of time may trigger spam filters.

December 2024 - GMass

What the experts say
3Expert opinions

Email experts approach customer deliverability troubleshooting in various ways. One expert avoids individual mail delivery issues, considering it outside their scope. Others emphasize the importance of sender reputation monitoring, involving analyzing bounce rates, complaints, and engagement. Additionally, ensuring proper sender authentication through SPF, DKIM, and DMARC is seen as crucial for verifying identity and building trust with mailbox providers.

Key opinions

  • Reputation: Understanding and monitoring sender reputation is crucial for identifying deliverability issues.
  • Authentication: Proper sender authentication (SPF, DKIM, DMARC) is a fundamental step in troubleshooting.
  • Triaging: Some experts avoid troubleshooting single mail delivery problems due to scope or difficulty.

Key considerations

  • Scope of work: Determine the scope of deliverability troubleshooting efforts; some issues may fall outside the responsibility of certain experts.
  • Metrics analysis: Analyze bounce rates, complaint rates, and engagement metrics to gain insights into sender reputation.
  • Authentication Protocols: Ensure SPF, DKIM, and DMARC are correctly implemented to verify sender identity and improve deliverability.
Expert view

Expert from Word to the Wise explains that a fundamental step in troubleshooting deliverability is ensuring proper sender authentication. This includes implementing SPF, DKIM, and DMARC to verify your identity and prevent email spoofing, ultimately building trust with mailbox providers.

November 2023 - Word to the Wise
Expert view

Expert from Spam Resource shares that understanding and monitoring your sender reputation is key. This involves analyzing bounce rates, complaint rates, and engagement metrics to identify and address issues negatively impacting deliverability.

December 2024 - Spam Resource
Expert view

Expert from Email Geeks explains that they refuse to troubleshoot single mail delivery problems, as it's outside their job description and that they are the worst to deal with.

December 2021 - Email Geeks

What the documentation says
5Technical articles

Email experts and documentation emphasize several key strategies for troubleshooting customer deliverability issues. These include adhering to bulk sender guidelines, particularly setting up SPF, DKIM, and DMARC for email authentication, maintaining low spam rates, and actively monitoring sender reputation using tools like Postmaster Tools. Avoiding spam filters by using a dedicated IP address and ensuring clean content is also important. Furthermore, implementing feedback loops with ISPs allows for the removal of subscribers who mark emails as spam, thus improving sender reputation.

Key findings

  • Authentication: SPF, DKIM, and DMARC are essential for email authentication and preventing spoofing.
  • Sender Reputation: Monitoring sender reputation is crucial for identifying and addressing deliverability issues.
  • Spam Prevention: Following best practices to avoid spam filters is critical for inbox placement.
  • Feedback Loops: Feedback loops provide valuable data on spam complaints, allowing for list cleaning.

Key considerations

  • Bulk Sender Guidelines: Adhere to specific guidelines provided by mailbox providers like Gmail and Microsoft.
  • Dedicated IP: Consider using a dedicated IP address for sending to improve reputation and control.
  • Content Quality: Ensure email content does not trigger spam filters by avoiding certain words and design elements.
  • DNS Records: Properly configure DNS records for SPF to authorize sending mail servers.
Technical article

Documentation from RFC specifies the technical standard for DMARC (Domain-based Message Authentication, Reporting & Conformance), which helps email senders protect their domains from unauthorized use, commonly known as email spoofing.

April 2024 - RFC
Technical article

Documentation from Microsoft Learn outlines best practices for avoiding spam filters, including authenticating email with SPF, DKIM, and DMARC, using a dedicated IP address, and ensuring content doesn't trigger spam filters.

July 2022 - Microsoft Learn
Technical article

Documentation from Auth0 shares that an SPF record is a TXT record in your domain's DNS that specifies which mail servers are authorized to send email on behalf of your domain. This helps prevent spoofing and improves email deliverability.

January 2025 - Auth0
Technical article

Documentation from SparkPost explains the importance of setting up feedback loops with ISPs. Feedback loops provide information about subscribers who mark your emails as spam, allowing you to remove them from your list and improve your sender reputation.

March 2022 - SparkPost
Technical article

Documentation from Gmail Help explains that to troubleshoot deliverability, bulk senders should follow Gmail's bulk sender guidelines, including setting up SPF, DKIM, and DMARC, keeping spam rates low, and monitoring their reputation using Postmaster Tools.

November 2024 - Gmail Help