Summary
To resolve high bounce rates and 'mailbox unavailable' errors for a specific domain, experts and documentation recommend a multi-faceted approach centered on diligent list hygiene. The foundational step involves promptly ceasing mailings to problematic addresses and removing invalid email addresses identified by 'mailbox unavailable' errors, as these indicate non-existent recipients. Email verification tools are essential for validating addresses, and regular list cleaning is crucial. Employing double opt-in and preference centers helps prevent future bounces. If bounces are domain-specific, contacting the IT department of that domain is advised. Standardized bounce messages and codes should be analyzed for insights. Aim for a bounce rate below 2%. Re-engagement campaigns can salvage potentially valid addresses, but a risk-benefit analysis is critical before continuing mailings to questionable addresses, considering the impact on sender reputation and deliverability.
Key findings
- Mailbox Unavailable = Non-Existent: A 'mailbox unavailable' error typically signifies that the recipient's email address does not exist.
- Immediate Removal of Hard Bounces: Hard bounces should be removed from your mailing list immediately to maintain sender reputation.
- List Hygiene is Crucial: Regularly cleaning and validating your email list is fundamental for minimizing bounces.
- Domain-Specific Issues Require Direct Contact: If bounces are concentrated on a specific domain, contact their IT department to resolve potential blocking issues.
- Double Opt-In Prevents Invalid Addresses: Implementing double opt-in helps to ensure that only valid email addresses are added to your list.
- Aim for <2% Bounce Rate: Strive to maintain a bounce rate of less than 2% for optimal email deliverability.
Key considerations
- Sender Reputation at Risk: High bounce rates negatively impact sender reputation, potentially leading to deliverability problems.
- Balance Revenue vs. Deliverability: Weigh the potential revenue from questionable email addresses against the risk to overall deliverability.
- Analyze Bounce Messages and Codes: Carefully examine bounce messages and codes to diagnose the underlying causes of delivery failures.
- Re-Engagement Campaigns: Consider using re-engagement campaigns to verify potentially valid addresses before removing them.
- Impact of Old vs. New Lists: Bounces might be due to an old list.
What email marketers say
8 marketer opinions
To resolve high bounce rates and 'mailbox unavailable' errors for a specific domain, email marketers recommend focusing on list hygiene through regular cleaning, validation of email addresses before sending, and immediate removal of hard bounces. Implementing double opt-in and preference centers helps prevent bounces. Addressing domain-specific issues involves contacting the IT department of the affected domain to resolve any blocks. Aim for a bounce rate below 2% and engage email verification tools to ensure valid email addresses. Soft bounces should be monitored but not immediately removed.
Key opinions
- List Hygiene: Regularly clean your email list by removing invalid addresses and inactive subscribers.
- Double Opt-In: Use double opt-in to ensure subscribers have explicitly given permission to receive emails.
- Hard Bounce Removal: Immediately remove hard bounces from your list to maintain a good sender reputation.
- Domain Contact: Contact the IT department of the problematic domain to resolve blocks.
- Verification Tools: Utilize email verification tools to confirm the validity of email addresses.
- Good Bounce Rate: Aim for a bounce rate of below 2% to ensure good deliverability.
Key considerations
- Sender Reputation: High bounce rates negatively impact sender reputation, affecting overall deliverability.
- Email Validation: Validating email addresses helps prevent sending to invalid or non-existent mailboxes.
- Soft vs. Hard Bounces: Differentiate between soft and hard bounces; soft bounces may resolve themselves, while hard bounces require immediate action.
- Re-engagement: Consider sending re-engagement emails to confirm subscriber interest before removing them.
- Specific Domain Issues: If issues are isolated to one domain, direct communication with their IT department is crucial.
- Preference Center: Consider implementing a preference center to allow subscribers to manage their communication preferences.
Marketer view
Email marketer from Reddit User u/EmailExpert responds to a question of what to do with hard bounces. They recommend immediately removing hard bounces as keeping them on your list indicates you are not keeping your list clean which will result in a worse reputation with the IPs. They further suggest sending a re-engagement email to confirm whether they still wish to be engaged.
31 May 2023 - Reddit
Marketer view
Email marketer from Reddit User u/DeliverabilityGuru responds to a question of what to do with soft bounces. They suggest a soft bounce is a temporary issue and typically resolves itself. They advise waiting a few days before removing an email from your email list.
29 Sep 2023 - Reddit
What the experts say
7 expert opinions
Experts recommend addressing high bounce rates and 'mailbox unavailable' errors for a specific domain by first identifying the cause, which often points to a bad or outdated email list. The advice is to cease mailing to those addresses, verify domain existence through DNS checks, and remove unresponsive recipients. Investigating bounce messages, reviewing sending practices, and potentially contacting the domain's postmaster are also recommended. A key consideration is balancing potential revenue loss from removing addresses against the risk to overall deliverability and sender reputation.
Key opinions
- Mailbox Unavailable: 'Mailbox unavailable' likely means the address no longer exists.
- Stop Mailing: Cease sending emails to problematic addresses immediately.
- Bad List: High bounce rates often indicate a poorly maintained or outdated email list.
- DNS Check: Verify the domain still resolves in DNS.
- Contact Postmaster: Attempt to contact the domain's postmaster for assistance.
Key considerations
- Deliverability Risk: Weigh the risk to deliverability against the potential revenue from questionable addresses.
- Lost Subscribers: Recognize that subscribers on the problematic list may already be lost.
- Bounce Message Analysis: Carefully analyze bounce messages for clues about the cause of the failures.
- Sending Practices: Review current sending practices for potential issues contributing to the problem.
- Revenue Data: If available, get data on lost revenue attributed to unsubscribed emails.
Expert view
Expert from Word to the Wise explains that if a domain is completely unresponsive and bouncing all mail, it could indicate the domain no longer exists. They advise checking if the domain resolves in DNS and if not, removing all recipients with that domain from your mailing lists.
7 Jan 2022 - Word to the Wise
Expert view
Expert from Email Geeks explains that a 'mailbox unavailable' error means the email address no longer exists and suggests that the client tried to bring over their bounces.
13 Feb 2022 - Email Geeks
What the documentation says
5 technical articles
Documentation consistently advises that to resolve high bounce rates and 'mailbox unavailable' errors, the primary action is to remove invalid email addresses from your contact list. 'Mailbox unavailable' errors signify permanent delivery failures and require immediate removal of those addresses to protect sender reputation. Standardized bounce messages and bounce codes provide detailed information for diagnosing the causes of delivery failures, facilitating automated processing and accurate identification of issues.
Key findings
- Remove Invalid Addresses: Eliminating invalid email addresses is crucial for reducing bounce rates.
- Mailbox Unavailable = Permanent Failure: 'Mailbox unavailable' errors indicate a permanent delivery failure.
- Immediate Hard Bounce Removal: Addresses causing hard bounces should be removed immediately.
- Bounce Message Information: Standardized bounce messages offer machine-readable details about delivery failures.
- Bounce Codes: Bounce codes provide specific information to help diagnose deliverability issues.
Key considerations
- Sender Reputation Impact: High bounce rates harm sender reputation, so it's vital to maintain a clean list.
- Automated Processing: Leverage automated systems to process bounce messages for efficient list management.
- Diagnostic Importance: Understanding bounce codes is essential for diagnosing and addressing underlying issues with email delivery.
- Data Driven Decisions: Make data driven decisions, remove recipients if the issue persists after verification.
Technical article
Documentation from Google Workspace Admin Help explains that to reduce bounce rates, you should remove invalid email addresses from your contact list. They recommend regularly cleaning your list by removing unsubscribed users and correcting typos.
3 Jun 2024 - Google Workspace Admin Help
Technical article
Documentation from SparkPost explains that 'mailbox unavailable' errors (hard bounces) indicate a permanent delivery failure. They advise immediately removing these addresses from your list to prevent further damage to your sender reputation.
13 Jul 2022 - SparkPost
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