Should I send emails to a list with a high hard bounce rate and how to prevent them?

Summary

Experts and email marketers strongly advise against sending emails to lists with high hard bounce rates due to significant damage to sender reputation, deliverability, and increased risk of being marked as spam. Preventing high bounce rates involves implementing best practices for list acquisition (confirmed opt-in, captcha, real-time validation), regular list cleaning to remove invalid addresses, maintaining suppression lists, and promptly processing bounces. Differentiating between hard and soft bounces is crucial, with hard bounces requiring immediate removal and soft bounces needing monitoring. Using email validation services is also recommended.

Key findings

  • Negative Impact: High hard bounce rates damage sender reputation and deliverability, potentially leading to blocking by ESPs.
  • List Acquisition: Poor acquisition practices (lack of opt-in, etc.) lead to high bounce rates and spam traps.
  • List Cleaning: Regular cleaning removes invalid emails, improving engagement.
  • Validation Services: Validation services identify and remove invalid emails proactively.
  • Purchased Lists (Bad): Purchased lists have high bounce rates and spam complaints; avoid them.
  • Bounce Rate Thresholds: Target bounce rates below 2%; rates above 5% demand immediate action.
  • Hard vs Soft Bounces: Hard bounces are permanent failures; soft bounces are temporary and should be monitored.
  • Bounce Processing: Prompt and accurate bounce processing is vital.

Key considerations

  • Investigate Sources: Analyze email address sources to identify problematic origins.
  • Implement Opt-in: Use confirmed opt-in methods for list verification.
  • Email Validation: Implement email validation on signup forms.
  • Monitor Reactivity: Analyze reactivity of remaining addresses after initial sends (small lists).
  • Suppression Lists: Maintain a suppression list of unsubscribes and bounces.
  • Tooling: Utilize external tools and services for list hygiene.
  • Bounce Type Differentiation: Differentiate and handle hard and soft bounces accordingly.
  • Message Interpretation: Understand and act on bounce back messages.

What email marketers say
11Marketer opinions

Experts and email marketers overwhelmingly advise against sending emails to lists with high hard bounce rates due to the significant negative impact on sender reputation, deliverability, and potential for being marked as spam. They recommend focusing on preventing high bounce rates by implementing best practices for list acquisition, such as confirmed opt-in and email validation, regularly cleaning email lists to remove invalid addresses, and maintaining suppression lists.

Key opinions

  • Negative Impact: High hard bounce rates damage sender reputation and deliverability, leading to potential blocking by ESPs.
  • List Acquisition: Poor list acquisition practices (e.g., lack of opt-in) contribute to high bounce rates and spam trap issues.
  • List Cleaning: Regular list cleaning is crucial for removing invalid emails and improving engagement metrics.
  • Validation Services: Email validation services can help identify and remove invalid emails before sending.
  • Purchased Lists: Avoid using purchased email lists as they typically have high bounce rates and spam complaints.
  • Bounce Rate Thresholds: A good bounce rate should be below 2%; rates above 5% require immediate attention.

Key considerations

  • Investigate Sources: Analyze the sources of email addresses to identify and exclude problematic origins.
  • Implement Opt-in: Use confirmed opt-in methods to ensure subscribers have actively verified their email address.
  • Email Validation: Implement real-time email verification on signup forms, along with captcha to protect forms.
  • Monitor Reactivity: For small lists, analyze the reactivity of remaining addresses after initial sends.
  • Suppression Lists: Maintain a suppression list of unsubscribed or bounced emails to prevent future sends.
  • Tooling: Use external tools or services to aid in the cleaning and validation process.
Marketer view

Email marketer from Neil Patel's Blog emphasizes the importance of regular list cleaning to remove inactive or invalid emails. List cleaning improves engagement metrics, deliverability and prevents you from being marked as spam.

April 2022 - Neil Patel's Blog
Marketer view

Email marketer from MailerCheck Blog advises that a good bounce rate should be below 2%, with anything between 2-5% needing attention, and over 5% being a cause for concern that requires immediate action. High bounce rates damage sender reputation and deliverability.

November 2021 - MailerCheck Blog
Marketer view

Expert from Email Geeks suggests using an external tool to eliminate invalid emails and improving the email acquisition method, which is clearly flawed.

August 2021 - Email Geeks
Marketer view

Email marketer from Reddit discusses the use of email validation services to identify and remove invalid emails before sending. They suggest that it's a worthwhile investment for list hygiene.

March 2022 - Reddit
Marketer view

Email marketer from Email on Acid clarifies that high bounce rates negatively impact sender reputation, increasing the likelihood of emails being filtered as spam, even for valid subscribers.

November 2023 - Email on Acid
Marketer view

Email marketer from Omnisend emphasizes the need to maintain a suppression list of unsubscribed or bounced emails to avoid sending to them again. This prevents further damage to sender reputation.

May 2022 - Omnisend
Marketer view

Email marketer from Email Marketing Forum warns against using purchased email lists due to their often-high bounce rates and spam complaints, advising focusing on organic list growth instead.

June 2022 - Email Marketing Forum
Marketer view

Email marketer from Email Geeks advises against sending to a list with a 12% hard bounce rate. They suggest investigating the history and source of the addresses to identify problematic sources. If the list is small, they recommend analyzing the reactivity of the remaining addresses after the initial send and questioning the value of continuing to email unresponsive contacts.

September 2022 - Email Geeks
Marketer view

Email marketer from ActiveCampaign explains that sending to a list with high hard bounce rates will damage your sender reputation and your deliverability rates, with ESPs potentially blocking your emails as a result.

October 2024 - ActiveCampaign
Marketer view

Email marketer from Campaign Monitor suggests focusing on collecting high-quality email addresses through methods like offering valuable incentives for sign-ups and using clear and concise sign-up forms.

August 2021 - Campaign Monitor
Marketer view

Email marketer from Email Geeks indicates that a 12% hard bounce rate suggests a failure to follow best practices in list acquisition, such as confirmed opt-in, captcha, and real-time email verification. They also warn of the potential for spam trap email addresses in the list.

December 2023 - Email Geeks

What the experts say
2Expert opinions

Experts emphasize the importance of proper bounce processing and list management to maintain a good sending reputation. This includes promptly and accurately handling bounces and regularly removing invalid or decayed email addresses from your list. Hard bounces should always be removed, and soft bounces should be regularly suppressed.

Key opinions

  • Bounce Processing: Prompt and accurate bounce processing is vital for maintaining a good sending reputation.
  • List Decay: Email lists naturally decay over time due to various reasons.
  • Hard Bounce Removal: Hard bounces should always be immediately removed from your email list.
  • Soft Bounce Suppression: Soft bounces should be regularly suppressed to maintain list hygiene.

Key considerations

  • List Management: Regularly manage your email list by removing addresses that are no longer valid.
  • Reputation Monitoring: Pay close attention to your sender reputation to detect and address any issues caused by bounces.
  • Automated Bounce Handling: Implement automated bounce handling mechanisms to ensure timely processing.
Expert view

Expert from Spam Resource details the process required to handle email bounces. Processing bounces promptly and accurately is very important to maintaining a good sending reputation.

May 2024 - Spam Resource
Expert view

Expert from Word to the Wise explains that email lists decay for several reasons, and it is important to manage your list well and remove addresses that are no longer any good. You should always remove hard bounces, and should regularly suppress soft bounces.

May 2023 - Word to the Wise

What the documentation says
4Technical articles

Documentation from various email service providers emphasizes the importance of distinguishing between hard and soft bounces. Hard bounces indicate permanent delivery failures and should be immediately removed from mailing lists, while soft bounces are temporary and require monitoring. Implementing double opt-in helps prevent invalid or misspelled emails from entering lists, reducing overall bounce rates. Understanding bounce back messages is also crucial for identifying failure reasons and improving list maintenance.

Key findings

  • Hard vs. Soft Bounces: Hard bounces are permanent failures; soft bounces are temporary.
  • Hard Bounce Removal: Hard bounces must be immediately removed from mailing lists.
  • Double Opt-in Benefits: Double opt-in reduces invalid emails and bounce rates.
  • Bounce Message Analysis: Understanding bounce back messages aids troubleshooting.

Key considerations

  • Bounce Type Differentiation: Properly identify and categorize hard and soft bounces.
  • Automated Removal: Implement automated systems for hard bounce removal.
  • Opt-in Process: Incorporate double opt-in to improve list quality from the start.
  • Message Interpretation: Develop a process for interpreting and acting on bounce back messages.
Technical article

Documentation from Google Workspace explains that understanding bounce back messages (Non-Delivery Reports) helps identify the reason for delivery failure, enabling better troubleshooting and list maintenance.

September 2024 - Google Workspace
Technical article

Documentation from SendGrid explains that hard bounces indicate a permanent reason for failed delivery (invalid email, domain doesn't exist), while soft bounces are temporary issues (full inbox, server down). Hard bounces should be removed immediately; soft bounces need monitoring.

August 2021 - SendGrid
Technical article

Documentation from SparkPost details the different types of bounces and how to handle them. It specifies the need to remove hard bounces immediately from the mailing list and implement a feedback loop.

March 2022 - SparkPost
Technical article

Documentation from Mailjet explains that using double opt-in (requiring subscribers to confirm their email address) helps prevent invalid or misspelled emails from entering your list, thereby reducing bounce rates.

October 2022 - Mailjet