Summary
The consensus from marketers, experts, and technical documentation is that managing soft bounces from full mailboxes requires a balanced approach. Resending emails can be a strategy, especially with segmented re-engagement campaigns, but aggressive resending is discouraged. Maintaining excellent list hygiene through regular cleaning, suppressing consistently bouncing addresses, and implementing sunset policies is vital. Technical documentation emphasizes that mailbox providers learn from bounce patterns, impacting deliverability. Overall, monitoring bounce rates (keeping them below 2%), prioritizing engagement, and employing careful bounce processing are key to maintaining a healthy sender reputation.
Key findings
- Acceptable Bounce Rate: A good bounce rate is generally below 2%; higher rates can negatively impact sender reputation.
- Resend with Caution: Resending to soft bounces, particularly due to full mailboxes, can be risky and requires careful segmentation and re-engagement strategies.
- List Hygiene is Key: Maintaining a clean email list by removing unengaged subscribers and consistently bouncing addresses is critical for deliverability.
- System Learning: Major email platforms like Gmail and Exchange Online learn from bounce patterns and adjust filtering accordingly.
- Sunset Policies: Implementing robust sunset policies to remove unengaged users improves deliverability.
Key considerations
- Time Period Between Bounces: Consider the time period between bounces; frequent bounces may indicate a permanent issue.
- User Engagement History: Take into account a user's engagement history when deciding whether to resend or suppress them.
- Mailing Frequency Impact: Mailing frequency influences the time frame for sunsetting unengaged users.
- Signup Source Relevance: The method by which a user signed up can impact their engagement and deliverability.
- VERP Implementation: Using VERP for accurate bounce tracking and automatic suppression is recommended.
- Bounce Monitoring Importance: Actively monitor bounce reports and take action on persistent errors to maintain a healthy sender reputation.
What email marketers say
13 marketer opinions
Experts generally agree that resending emails to users with soft bounces due to full mailboxes requires a nuanced approach. While some suggest retrying a few times, it's crucial to monitor the bounce rate and user engagement to protect sender reputation. A consensus is that continuously resending without segmentation or re-engagement strategies can be risky and harm deliverability. Maintaining list hygiene, sunsetting unengaged users, and closely monitoring bounce rates are essential for successful email marketing.
Key opinions
- Bounce Rate Threshold: A bounce rate below 2% is generally considered acceptable, while exceeding this may indicate deliverability issues.
- Resend Strategy: Resending to soft bounces should be limited and combined with strategies such as list segmentation and re-engagement campaigns.
- List Hygiene: Maintaining a clean email list by removing unengaged subscribers and consistently bouncing addresses is crucial.
- Suppression: Persistent soft bounces, particularly those due to full mailboxes, should lead to suppression to avoid damaging sender reputation.
Key considerations
- Engagement History: Consider a user's past engagement when deciding whether to resend emails after a soft bounce.
- Time Between Bounces: The time elapsed between soft bounces provides context: frequent bounces suggest a permanent issue.
- Mailing Frequency: The frequency of your email sends influences how quickly unengaged users should be sunsetted.
- Signup Method: The method by which users subscribed can impact their engagement level and likelihood of clearing their mailbox.
- Segmentation: Segmenting your audience based on engagement and bounce history allows for more targeted and effective re-engagement efforts.
Marketer view
Email marketer from Reddit explains the key difference between hard and soft bounces. They suggest you should never send to a hard bounce, but soft bounces should be retried a few times. If they persist, it is best to remove them to improve your email reputation
12 Aug 2021 - Reddit
Marketer view
Email marketer from HubSpot answers that a bounce rate above 2% is cause for concern. They suggest that a high bounce rate can indicate issues with list hygiene or sending practices. They recommend cleaning lists and only emailing engaged contacts.
27 Jan 2023 - HubSpot
What the experts say
2 expert opinions
Experts emphasize the importance of proactive list management and careful bounce processing for maintaining email deliverability. They advise against aggressive resending to full mailboxes, highlighting the need for robust sunset policies and prioritizing engagement. Accurate bounce tracking and automatic suppression of invalid addresses are also recommended to safeguard sender reputation.
Key opinions
- List Hygiene Priority: Focusing on list hygiene is crucial for managing soft bounces effectively.
- Limited Resending: Aggressive resending strategies, especially to full mailboxes, are not recommended.
- Sunset Policies: Implementing a robust sunset policy is vital for maintaining a healthy sender reputation.
- Accurate Bounce Tracking: Using VERP (Variable Envelope Return Path) helps accurately track bounces and automatically suppress invalid addresses.
Key considerations
- Engagement Prioritization: Prioritize engagement to maintain a healthy sender reputation.
- Bounce Processing Implementation: Implement proper bounce processing to automatically suppress invalid addresses.
- Address Validity: Validity of email addresses should be a high consideration to protect sender reputation
Expert view
Expert from Spam Resource explains that bounce processing is key to maintaining deliverability. They recommend that senders use VERP (Variable Envelope Return Path) to accurately track bounces and automatically suppress invalid addresses. They recommend only retrying a small number of soft bounces.
4 Aug 2021 - Spam Resource
Expert view
Expert from Word to the Wise explains that focusing on list hygiene is crucial for managing soft bounces. She recommends against aggressive resending strategies, especially to full mailboxes. Instead, she advises implementing a robust sunset policy and prioritizing engagement to maintain a healthy sender reputation.
28 Oct 2024 - Word to the Wise
What the documentation says
3 technical articles
Technical documentation from RFC, Microsoft, and Google indicates that repeated soft bounces, such as those due to full mailboxes, should be treated with caution. SMTP servers use response codes to signal mailbox issues, and major email platforms like Exchange Online and Gmail employ bounce detection algorithms. These systems learn from bounce patterns, and high bounce rates can lead to deliverability problems, including messages being marked as spam or senders being temporarily blocked. Maintaining clean and engaged mailing lists is essential to avoid these issues.
Key findings
- SMTP Codes: SMTP server response codes like '4.2.2' often indicate full mailboxes.
- Automated Learning: Email platforms like Gmail learn from bounce patterns.
- Negative Impact: High bounce rates can cause deliverability issues and spam filtering.
- Escalation: Multiple soft bounces can eventually be treated as hard bounces by systems like Exchange Online.
Key considerations
- Bounce Monitoring: Actively monitor bounce reports to identify and address persistent errors.
- List Management: Implement rigorous list cleaning practices to remove invalid or unengaged addresses.
- Error Handling: Treat repeated soft bounce failures as potential permanent errors.
- List Engagement: Maintaining clean and engaged mailing lists is paramount to ensure high deliverability
Technical article
Documentation from Google answers that Gmail's systems automatically learn from bounce patterns. They say that senders with high bounce rates may experience deliverability issues, including messages being routed to spam folders. They stress the importance of maintaining clean and engaged mailing lists.
11 Mar 2023 - Google
Technical article
Documentation from Microsoft answers that Exchange Online uses sophisticated bounce detection algorithms. They say that multiple soft bounces from the same address can eventually lead to the address being treated as a hard bounce, and the sender may be temporarily blocked. They recommend monitoring bounce reports and taking action on persistent errors.
8 Jul 2024 - Microsoft
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