Summary
Cleaning up soft bounces in email marketing is crucial for maintaining a healthy sender reputation and ensuring optimal deliverability. Unlike hard bounces, which indicate permanent delivery failures, soft bounces are temporary. They can occur for various reasons, such as a recipient's inbox being full, the server being temporarily unavailable, or the email size exceeding limits. However, persistent soft bounces for a particular address can signal a deeper issue, like an inactive mailbox or a domain with consistent deliverability problems.
Key findings
- Consecutive bounces: A common best practice suggests suppressing (or removing) contacts after a certain number of consecutive soft bounces, for example, 3 to 5 soft bounces over a period like 21 days or 10 weeks.
- Dynamic counter: If an email successfully delivers to an address that had previously soft bounced, the soft bounce counter for that address should be reset. This acknowledges that temporary issues can resolve themselves.
- Contextual classification: Not all soft bounces are equal. It is important to differentiate between soft bounces due to a full mailbox (which might be temporary) and those related to IP reputation or spam filters (which indicate a broader deliverability issue).
- Proactive hygiene: Regularly cleaning your email list and employing methods like double opt-in are crucial for minimizing soft bounces and maintaining overall list hygiene.
Key considerations
- Define soft bounce: Ensure a clear definition of what constitutes a soft bounce in your system, distinguishing between temporary rejections and mail that was queued and retried.
- Establish a suppression threshold: Determine a specific number of soft bounces and a timeframe after which an email address will be suppressed or removed from active lists. Consider what is a reasonable soft bounce tolerance.
- Automate processes: Implement automated systems to track soft bounces, apply suppression logic, and re-engage or sunset inactive subscribers, which is a key part of reducing email bounce rate.
- Monitor deliverability metrics: Continuously monitor your bounce rates and other key deliverability metrics to identify trends and adjust your cleanup strategy as needed.
What email marketers say
Email marketers often face the challenge of managing soft bounces, which are temporary delivery failures. While a soft bounce doesn't mean an email address is permanently invalid, repeated soft bounces can indicate an issue that needs attention to maintain a healthy email list and sender reputation. Many marketers adopt specific rules for suppressing or removing contacts based on the frequency and consistency of these bounces.
Key opinions
- Rule-based suppression: Many marketers use a rule-based approach, such as removing contacts after 3-5 consecutive soft bounces over a set period. This provides a balance between leniency for temporary issues and proactive list hygiene.
- Percentage-based removal: Some marketers identify and remove emails that soft bounce a very high percentage of the time (e.g., 95%) within a given timeframe, recognizing these as effectively garbage domains or persistently full mailboxes.
- Double opt-in importance: Implementing double opt-in for new subscribers is frequently cited as a foundational step to reduce bad addresses and, consequently, soft bounces from the outset.
- Regular list cleaning: Consistent email list cleaning (removing duplicates, hard bounces, and cold subscribers) is universally recommended as a primary strategy to lower bounce rates and improve deliverability.
Key considerations
- Client-specific metrics: Bounce rates and acceptable soft bounce thresholds can vary significantly between clients and industries, necessitating a flexible approach.
- Distinguish bounce types: Marketers must understand the nuances of soft bounce reasons (e.g., temporary server issues versus persistent full mailboxes) to apply the most appropriate cleanup actions.
- Impact on sender reputation: Failing to manage soft bounces can negatively impact sender reputation, leading to more emails landing in spam folders or being placed on a blocklist.
- Proactive email validation: Before sending, using an email validation service can help identify invalid addresses upfront, reducing both hard and soft bounces. This aligns with best practices for email verification.
Marketer view
Marketer from Email Geeks suggested that a client was looking to implement a rule for removing contacts based on a threshold of soft bounces within a specific timeframe, such as 5 soft bounces over 10 weeks.
Marketer view
Marketer from Klaviyo states that ensuring the email addresses you send to are real and consented profiles is essential. They also recommend enabling double opt-in to confirm that new subscribers genuinely wish to receive your emails.
What the experts say
Experts emphasize that while soft bounces are temporary, their effective management is critical for maintaining a strong sender reputation and ensuring long-term email deliverability. They highlight the importance of defining soft bounces precisely and implementing sophisticated suppression logic that considers the nature of the bounce and past delivery success.
Key opinions
- Defined suppression rules: Experts commonly suggest a rule like "at least 3 consecutive soft bounces over at least 21 days" to balance hygiene with the temporary nature of these issues.
- Reset counter on delivery: Crucially, if an email successfully delivers, the soft bounce counter for that address should be reset, as the temporary issue has resolved.
- Bounce category analysis: It is vital to categorize soft bounces (e.g., mailbox full vs. spam-related rejection) to apply appropriate cleanup rules, as not all soft bounces indicate a problem with the recipient's address itself.
- Beyond spam/bad addresses: Delivery failures can stem from various causes beyond just spam blocks or invalid addresses, requiring a nuanced approach to troubleshooting and cleanup.
Key considerations
- Granular soft bounce definition: Define soft bounces precisely in your system as 'mail temporarily rejected until the system gives up,' rather than merely 'queued and retried,' to ensure accurate classification.
- Avoid over-suppression: While hygiene is key, avoid overly aggressive suppression that might prematurely remove engaged subscribers who experienced only temporary delivery issues. Review suppression logic.
- Continuous monitoring: Use tools like Google Postmaster Tools or other deliverability platforms to monitor bounce rates and categorize bounce types for informed decision-making. This can help with understanding soft bounces and fixing them.
- Integration with CRM: Integrate bounce management with your CRM or marketing automation platform to automatically update contact statuses and prevent future sends to consistently bouncing addresses. Refer to Salesforce Marketing Cloud's bounce handling for example.
Expert view
Expert from Email Geeks suggests that a reasonable rule for soft bounce cleanup is to suppress contacts after at least three consecutive soft bounces observed over a minimum of 21 days.
Expert view
Expert from SpamResource emphasizes the importance of understanding the specific reasons for soft bounces, as different temporary errors require varied handling strategies to maintain sender reputation effectively.
What the documentation says
Official documentation from various email service providers and deliverability experts consistently emphasizes the importance of managing soft bounces to maintain good sender reputation. They outline the typical causes of soft bounces and recommend a combination of preventative measures and reactive cleanup strategies to ensure optimal email deliverability.
Key findings
- Temporary nature: Documentation defines soft bounces as temporary failures, distinguishing them from hard bounces which are permanent.
- Common causes: Typical reasons for soft bounces include full mailboxes, server downtime, or large email sizes exceeding limits.
- List hygiene importance: Regular email list cleaning is a frequently recommended practice for reducing overall bounce rates, including soft bounces.
- Preventative measures: Using double opt-in and ensuring email addresses are valid from the start are highlighted as crucial preventative steps.
Key considerations
- Maintain acceptable bounce rates: Documentation often suggests an ideal total bounce rate (including soft and hard bounces) to aim for, typically around 2% or less, to ensure healthy sending. This relates to soft bounce tolerance.
- Automated bounce processing: Email platforms advise using automated systems to process bounces and automatically suppress addresses after a defined number of soft bounce occurrences, as detailed in recommended suppression logic.
- Content and technical checks: Beyond list hygiene, review email content for spam trigger words and ensure proper authentication (SPF, DKIM, DMARC) to avoid soft bounces due to spam filters. You can check your blocklist status.
- Inactivity management: Some documentation suggests implementing strategies for sunsetting inactive subscribers, as their mailboxes may eventually lead to soft bounces.
Technical article
Documentation from Mailgun defines soft bounces as temporary delivery failures. These often occur due to a recipient's full inbox or a temporary server issue, and they provide methods to address these transient problems.
Technical article
Documentation from CXL asserts that maintaining good list hygiene is the most crucial factor for reducing email bounce rates. This involves consistently monitoring your bounce rates, managing opt-ins, and tracking other key deliverability metrics.
Related resources
15 resources
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