Summary
Email marketers are encountering both hard and soft bounces, along with bounces caused by spam traps. Hard bounces, signifying permanent delivery failures due to invalid email addresses, should be immediately removed from mailing lists. Soft bounces, representing temporary issues like full mailboxes or server problems, can be retried. High bounce rates negatively impact sender reputation and may lead to emails being marked as spam. Proactive list cleaning, keeping bounce rates below 2-5%, monitoring bounce codes, utilizing tools like Google Postmaster Tools and avoiding spam traps are critical for maintaining healthy deliverability. Bounce classification helps determine whether an address should be removed or if the problem is temporary.
Key findings
- Hard vs. Soft Bounces: Bounces are categorized as hard (permanent failures) or soft (temporary issues).
- Impact on Reputation: High bounce rates negatively impact sender reputation and can lead to spam marking.
- Common Bounce Reasons: Reasons include invalid addresses, full mailboxes, unavailable servers, blocked senders, and spam filters.
- Spam Traps: Spam traps result in bounces that severely damage sender reputation.
- Bounce Rate Threshold: Maintaining a bounce rate below 2-5% is considered good practice.
- Bounce classification: Bounce classification helps determine whether an address should be removed or if the problem is temporary.
Key considerations
- List Cleaning: Proactively clean email lists to remove invalid or inactive addresses.
- Remove Hard Bounces: Immediately remove hard bounce addresses from the mailing list.
- Retry Soft Bounces: Consider retrying delivery to addresses that resulted in soft bounces, but monitor for repeated failures.
- Monitor Bounce Rates: Regularly monitor bounce rates and address the underlying causes of bounces, using tools like Google Postmaster Tools.
- Avoid Spam Traps: Implement strategies to avoid sending to spam traps, as they severely damage sender reputation.
- Utilize Bounce Codes: Use bounce codes to diagnose and address underlying issues.
What email marketers say
9 marketer opinions
Email marketers are seeing both hard and soft bounces. Hard bounces are permanent delivery failures due to invalid or non-existent email addresses and should be immediately removed from mailing lists. Soft bounces are temporary issues like full inboxes or server problems. High bounce rates negatively impact sender reputation and can lead to emails being marked as spam. Proactive list cleaning, keeping bounce rates below 2-5%, and avoiding spam traps are crucial for maintaining healthy deliverability.
Key opinions
- Hard vs Soft Bounces: Bounces are categorized as hard (permanent failure) or soft (temporary issue).
- Impact on Reputation: High bounce rates negatively impact sender reputation.
- Bounce Rate Calculation: Bounce rates are calculated as a percentage of total emails sent, indicating list health.
- Common Bounce Reasons: Common reasons include invalid addresses, blocked senders, and spam filters.
- Spam Traps: Spam traps often result in bounces that severely damage sender reputation.
Key considerations
- List Cleaning: Proactively clean email lists to remove invalid or inactive addresses.
- Bounce Rate Threshold: Maintain a bounce rate below 2% to 5% for healthy deliverability.
- Monitoring: Regularly monitor bounce rates and address the underlying causes of bounces.
- Sender Reputation: Protect your sender reputation by minimizing bounces and spam complaints.
- Soft bounce re-engagement: Consider a soft bounce re-engagement strategy, as soft bounces are temporary.
Marketer view
Email marketer from Sendinblue says maintaining a bounce rate below 2% to 5% is considered good practice to ensure healthy deliverability.
16 Nov 2023 - Sendinblue
Marketer view
Email marketer from HubSpot details how email bounce rates are calculated as a percentage of total emails sent. Monitoring this rate is a key indicator of list health.
23 Dec 2022 - HubSpot
What the experts say
3 expert opinions
Experts indicate email marketers are seeing both hard and soft bounces. Hard bounces represent permanent delivery failures due to invalid email addresses that should be immediately removed from lists. Soft bounces are temporary issues, such as full mailboxes or server problems, and can be retried later. It's also critical to monitor bounces for illegitimate causes, such as spam traps, which can negatively impact sender reputation.
Key opinions
- Hard Bounce Definition: Hard bounces are permanent delivery failures caused by invalid email addresses.
- Soft Bounce Definition: Soft bounces are temporary delivery issues, like full mailboxes or server problems.
- Spam Trap Monitoring: Monitoring bounces for spam traps is crucial for protecting sender reputation.
Key considerations
- Remove Hard Bounces: Immediately remove hard bounce addresses from your email list.
- Retry Soft Bounces: Consider retrying delivery to addresses that resulted in soft bounces.
- Bounce Legitimacy: Analyze bounce reasons to differentiate legitimate bounces from those caused by spam traps.
Expert view
Expert from Word to the Wise explains some bounces are legit. You need to watch for bounces caused by things like spam traps.
20 Jan 2023 - Word to the Wise
Expert view
Expert from Spamresource explains soft bounces are temporary issues. This might be a full mailbox or a server problem. You can try resending to these addresses later.
26 Mar 2025 - Spamresource
What the documentation says
5 technical articles
Documentation indicates that email marketers are seeing bounces due to various reasons, including full mailboxes, unavailable servers, and invalid email addresses. Hard bounces should be removed from sending lists, while soft bounces are temporary failures. Bounce classification helps determine if an address should be removed or if the problem is temporary. Bounce codes provide a standardized way to understand delivery failures. Tools like Google Postmaster Tools can assist in monitoring bounce rates and improving email performance.
Key findings
- Bounce Reasons: Bounces occur due to reasons like full mailboxes, server unavailability, and invalid email addresses.
- Hard vs. Soft Bounces: Distinction between hard bounces (permanent failures) and soft bounces (temporary issues).
- Bounce Classification: Bounce classification helps determine whether to remove an address or retry.
- Bounce Codes: Bounce codes provide standardized information on why an email was not delivered.
- Monitoring Tools: Tools like Google Postmaster Tools help monitor bounce rates and improve performance.
Key considerations
- Remove Hard Bounces: Remove addresses that result in hard bounces from your sending list.
- Address Soft Bounces: Understand that continued soft bounces can lead to deliverability issues, and address appropriately.
- Utilize Bounce Codes: Use bounce codes to diagnose and address underlying issues.
- Monitor Bounce Rates: Use monitoring tools to track bounce rates and identify potential deliverability problems.
Technical article
Documentation from SparkPost details how bounce classification helps to determine whether the email address should be removed from the mailing list (hard bounce) or whether the problem is temporary (soft bounce).
23 Feb 2023 - SparkPost
Technical article
Documentation from RFC 3464 describes various bounce codes and their meanings, providing a standard way to understand why an email was not delivered.
14 Oct 2022 - RFC Editor
How do bounces impact email deliverability and how can I minimize them?
Can a hard bounced email address become deliverable again, and under what circumstances?
What are common email bounce messages and what do they mean?
Do soft bounces affect email deliverability and sender reputation?
How are email bounce rates calculated and what is considered a good bounce rate?
Can 'invalid recipient' bounce messages be false positives and what should I do about it?
