Summary
Sending to a new segment with a new sender address often leads to increased bounces due to a lack of established sender reputation and potential permission issues. Experts and marketers recommend warming up the new sender address and domain by gradually increasing sending volume. Maintaining good email list hygiene, including removing hard bounces (especially those marked as 'envelope blocked - User Entry') and validating new lists, is essential. Implementing email authentication (SPF, DKIM, DMARC) builds trust with email providers. Checking against blocklists, establishing consistent sending volumes, using double opt-in, and A/B testing content can further improve deliverability. Additionally, using a shared envelope domain can impact deliverability, making a custom envelope a worthwhile consideration. Understanding bounce types (soft vs. hard) and analyzing SMTP error codes are crucial for diagnosing and resolving delivery issues. Adhering to sending limits set by providers like Microsoft Exchange Online is also important.
Key findings
- Sender Reputation: New sender addresses lack established reputations, triggering spam filters and increasing bounces.
- List Hygiene: Invalid or inactive email addresses increase bounce rates; 'envelope blocked - User Entry' is a hard bounce.
- Authentication: Implementing SPF, DKIM, and DMARC improves deliverability by establishing trust with email providers.
- Blocklists: Being listed on blocklists negatively impacts deliverability.
- Sending Volume: Inconsistent sending volumes can damage sender reputation.
- Permission: Lack of explicit permission or outdated data leads to increased bounce rates.
- Shared Envelope: Using a shared envelope domain can cause deliverability issues due to the actions of other senders.
- Bounce Types: Soft bounces are temporary; hard bounces require immediate removal.
- Error Codes: SMTP error codes help diagnose delivery failures.
- Sending Limits: Exceeding sending limits can lead to bounces.
Key considerations
- Warm-up: Gradually warm up the IP address and domain to establish a sender reputation.
- List Validation: Validate new email lists to remove invalid addresses before sending.
- Hard Bounce Removal: Immediately remove addresses that generate hard bounces, especially 'envelope blocked - User Entry' bounces.
- Authentication: Configure SPF, DKIM, and DMARC records to authenticate emails.
- Opt-in: Use double opt-in to ensure recipients actively consent to receive emails.
- Content Optimization: A/B test subject lines and content to improve engagement and reduce spam complaints.
- List Hygiene: Regularly clean your email list to remove inactive or invalid addresses.
- Monitoring: Monitor sending statistics and bounce rates to identify and address issues proactively.
- Envelope Customization: Consider using a custom envelope to isolate your sending reputation.
- Sending Schedule: Establish a consistent sending schedule to avoid negatively impacting sender reputation.
- Unsubscribe Process: Implement a clear and easy way to unsubscribe from future emails.
What email marketers say
10 marketer opinions
Sending to a new email segment with a new sender address often leads to increased soft and hard bounces due to a lack of established sender reputation. Experts recommend warming up the new sender address and domain by gradually increasing sending volume. Maintaining good email list hygiene, including removing hard bounces and validating new lists, is essential. Implementing email authentication (SPF, DKIM, DMARC) builds trust with email providers. Checking against blocklists, establishing consistent sending volumes, using double opt-in, and A/B testing content can further improve deliverability.
Key opinions
- Sender Reputation: New sender addresses lack established reputations, triggering spam filters.
- List Hygiene: Invalid or inactive email addresses increase bounce rates.
- Authentication: Implementing SPF, DKIM, and DMARC improves deliverability.
- Blocklists: Being listed on blocklists can significantly impact deliverability.
- Sending Volume: Inconsistent sending volumes negatively affect sender reputation.
- Hard bounces: Envelope block user entry is a hard bounce
Key considerations
- Warm-up Period: Gradually increase sending volume from the new address to build reputation.
- List Validation: Validate new email lists to remove invalid addresses before sending.
- Opt-in Methods: Use double opt-in to ensure recipients actively consent to receive emails.
- Content Optimization: A/B test subject lines and content to improve engagement and reduce spam complaints.
- Monitoring: Regularly check your domain and IP address against blocklists. Ensure that your email infrastructure is correctly configured.
Marketer view
Email marketer from Sendinblue Blog explains that maintaining good email list hygiene by removing invalid or inactive email addresses can help reduce bounce rates and improve deliverability. Regularly clean your list.
12 Nov 2024 - Sendinblue Blog
Marketer view
Email marketer from Litmus Blog explains that A/B testing subject lines and email content can help improve engagement and reduce spam complaints, indirectly lowering bounce rates by improving overall sender reputation.
8 Nov 2023 - Litmus Blog
What the experts say
4 expert opinions
Sending to new segments with new sender addresses often leads to increased bounces due to a lack of established sender reputation and potential permission issues. Experts emphasize the importance of recipient permission, proper list hygiene, and gradually warming up the sender reputation. Using a shared envelope domain can also lead to issues, as actions by other users can impact your deliverability. Properly configuring email authentication protocols like SPF, DKIM, and DMARC is also crucial.
Key opinions
- Recipient Blocks: Recipients explicitly blocking the sender's address is a significant cause of bounces.
- Sender Reputation: A lack of established sender reputation triggers spam filters and increases bounces.
- Permission: Lack of explicit permission or outdated data can lead to increased bounce rates.
- Shared Envelope: Using a shared envelope domain can result in deliverability issues caused by other senders.
Key considerations
- List Removal: Immediately remove recipients who have explicitly blocked the sender.
- Warm-up: Gradually warm up the IP address and domain to establish a sender reputation.
- Opt-in: Confirm opt-in and maintain good list hygiene practices.
- Authentication: Ensure proper configuration of SPF, DKIM, and DMARC.
- Custom Envelope: If using shared envelope addresses, consider switching to custom envelopes to isolate sending reputation.
Expert view
Expert from Email Geeks explains that blocks may be triggered by other users sharing the same envelope domain and suggests using a custom envelope to isolate sending reputation. Because you are using a shared envelope domain blocks may be triggered by someone else using that domain.
5 Aug 2022 - Email Geeks
Expert view
Expert from Word to the Wise explains that permission is key, especially with new segments. Increased bounces can indicate a lack of permission or outdated data, and emphasizes the importance of confirming opt-in and practicing good list hygiene.
22 Jan 2025 - Word to the Wise
What the documentation says
6 technical articles
Addressing increased email bounces involves understanding bounce types, diagnosing issues using SMTP error codes, adhering to sending limits, implementing easy unsubscribe options, monitoring sending statistics, and authenticating your sending domain. Hard bounces indicate permanent issues and require immediate removal from the list, while understanding the nuances of soft bounces can help in troubleshooting temporary delivery problems. Email authentication with SPF and DKIM is crucial for establishing trust with email providers.
Key findings
- Bounce Types: Soft bounces are temporary; hard bounces are permanent and require removal.
- SMTP Codes: SMTP error codes provide insights into the reasons for delivery failures.
- Sending Limits: Exceeding sending limits can lead to temporary blocks and bounces.
- Unsubscribe Headers: List-Unsubscribe headers reduce spam complaints and potential bounces.
- Sending Statistics: Monitoring bounce rates and other metrics allows for proactive issue identification.
- Authentication: Authenticating your domain (SPF and DKIM) improves deliverability.
Key considerations
- Hard Bounce Removal: Immediately remove addresses that generate hard bounces from your mailing lists.
- Error Code Analysis: Analyze SMTP error codes to understand the cause of delivery problems and take appropriate action.
- Adherence to Limits: Ensure compliance with sending limits imposed by email service providers like Exchange Online.
- Easy Unsubscribe: Implement List-Unsubscribe headers for easy and accessible unsubscription options.
- Proactive Monitoring: Actively monitor sending statistics and bounce rates to identify and address potential issues early on.
- Domain Authentication: Set up SPF and DKIM records for your sending domain to authenticate your emails.
Technical article
Documentation from AWS explains that Amazon SES provides detailed sending statistics, including bounce rates. Monitor these metrics to identify and address deliverability issues proactively.
2 Mar 2025 - Amazon Web Services
Technical article
Documentation from RFC Standards explains that interpreting SMTP error codes provided in bounce messages can help diagnose the specific reasons for delivery failures. Different codes indicate different problems.
17 Apr 2023 - RFC Standards
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