What should I do if a user's email hard bounced and they aren't receiving emails?

Key findings

• Suppression lists: Hard bounces automatically add email addresses to suppression lists (also known as blocklists) to protect your sender reputation.
• Permanent failure: A hard bounce signifies a permanent reason for email non-delivery, meaning the address is likely invalid or non-existent.
• Customer service: For high-value customers, direct engagement is often warranted to understand the issue and resolve it, even if it means trying alternative contact methods.
• Platform variations: The ease of removing an address from a hard bounce suppression list varies significantly between different email platforms.
• Typo possibility: Sometimes, the original hard bounce may have been due to a simple typo, which can be corrected by the user.

Key considerations

• Reconfirmation: Always ask the user to reconfirm their email address to ensure accuracy and explicit consent. This can be done by asking them to re-enter it or to reply to a test email.
• Gmail aliases: For Gmail addresses, suggest the user try adding dots (e.g., first.last@gmail.com) or plus aliases (e.g., username+alias@gmail.com). These appear as new addresses to your ESP but deliver to the original inbox.
• Manual re-addition: Some ESPs allow manual re-addition of hard-bounced addresses. Explore this option cautiously and only after verifying the address's current validity. Learn more about how to manage hard bounced email addresses.
• Sender reputation: Be aware that continuously attempting to send to truly invalid hard-bounced addresses can negatively impact your sender reputation and lead to your domain being put on an email blacklist. Understanding how hard bounces impact deliverability is critical.
• Bounce vs. spam: Distinguish between a hard bounce (permanent delivery failure) and an email landing in the spam folder (successful delivery but incorrect placement). These require different troubleshooting approaches.
• Automated suppression: Most ESPs automatically suppress hard bounces. You can learn more about this process and its implications on resources like MailerSend's guide to bounced emails.

Key opinions

• Suppression list removal: A common first thought is to clear the user from the ESP's suppression list.
• Reconfirmation: Asking the user to reconfirm their email address, or provide a new one, is a widely suggested solution.
• Typo checks: Many marketers note that a hard bounce can sometimes be due to a simple typo in the email address.
• Spam folder consideration: It's important to differentiate between hard bounces and emails going to the spam folder, as troubleshooting differs.
• Platform capabilities: The ability to manage hard-bounced contacts varies depending on the specific email marketing platform being used.

Key considerations

• Manual overrides: Marketers may need to manually override automated suppression settings for specific, high-priority customer cases. This is part of best practices for reducing bounces.
• Customer communication: Engaging directly with the customer to explain the issue and provide solutions can improve satisfaction.
• Impact on reputation: While resolving a single customer's issue is important, consistently ignoring hard bounces can severely harm your sender reputation and lead to your emails going to a blocklist.
• Workflow automation: Some ESPs allow for specific workflows to re-add hard-bounced contacts under certain conditions, offering a scalable solution for known valid addresses. You can find out more about hard versus soft bounces on Shopify's blog.

Key opinions

• Gmail aliases: Experts often recommend the Gmail 'dot trick' or 'plus trick' for re-engaging users, as these create unique addresses for the ESP but route to the original inbox.
• ESP vs. Gmail view: While aliases appear as distinct emails to your ESP, Gmail treats them as the same recipient, allowing for bypass of suppression lists.
• Manual re-addition: Despite automated suppression, many ESPs permit manual re-addition of addresses, which can be useful for legitimate customers.
• Workflow solutions: Implementing specific workflows within your ESP can help manage re-engagement for hard-bounced contacts more efficiently.
• Beyond suppression: Sometimes issues perceived as hard bounces might actually be related to spam folder placement, requiring different solutions.

Key considerations

• Reputation risk: Experts warn that persistent attempts to email truly invalid addresses can severely damage your sender reputation, leading to blocklisting or poor inbox placement. This is critical for maintaining good domain reputation.
• Recipient confirmation: Any re-engagement with a hard-bounced contact should ideally be initiated with their explicit re-opt-in or confirmation.
• Bounce code analysis: Understanding specific SMTP bounce codes can provide deeper insights into the root cause of the hard bounce. You can learn why a valid email address might hard bounce.
• Proactive hygiene: Regular email list hygiene and verification are paramount to minimize hard bounces in the first place, as discussed on industry expert sites like CXL's guide on email bounce rate.

Key findings

• Permanent errors: Hard bounces are classified as emails that could not be delivered due to permanent, unresolvable issues, such as a non-existent email address.
• Suppression requirement: All documentation advises adding hard-bounced addresses to a suppression or blocklist immediately.
• Reputation protection: Suppressing hard bounces is crucial for safeguarding your sending reputation and avoiding being flagged as a spammer by internet service providers (ISPs).
• No resends: There is a strong consensus against attempting to resend emails to addresses that have hard bounced.
• List hygiene: Regular list cleaning and email verification are highlighted as essential preventative measures.

Key considerations

• Automated suppression: While many ESPs automatically handle hard bounce suppression, understanding their specific rules and triggers is vital for effective management. This directly impacts how hard and soft bounces are defined and managed.
• SMTP codes: Technical documentation often provides detailed explanations of various SMTP bounce codes, which can help diagnose the exact reason for the hard bounce and determine if it's truly permanent.
• Provider differences: Although general principles apply, the specific implementation of bounce handling and suppression can vary between different email service providers.
• Re-engagement pathways: Some documentation may outline specific, cautious methods for re-engaging contacts previously marked as hard bounce, often contingent on explicit re-opt-in. This aligns with asking whether a hard bounced email can become deliverable again.
• Authentication impact: Proper email authentication, such as SPF and DKIM, can sometimes prevent bounces related to unverified sending, as detailed by platforms like SendLayer.