What is useful bounce data for email marketing?

Email marketer from Reddit explains that setting up feedback loops with major ISPs provides valuable bounce data for identifying and removing spam traps from your email list.

Email marketer from Litmus shares that regularly analyzing bounce data and removing hard bounces from your list improves deliverability and sender reputation.

Email marketer from Email Geeks shares that he would include the entire exact and un-edited SMTP response in bounce data.

Email marketer from Email Geeks notes the DKIM algo should be included too, as there are more and more places starting to refuse sha-1.

Email marketer from Email Geeks shares that when you dig into exactly what some ESPs define soft and hard bounces as, it is frustrating.

Email marketer from Email Geeks explains that in the case of a post-acceptance bounce message, he'd like that entire message available in an XML blob, JSON or similar.

Email marketer from SendPulse shares that analyzing bounce codes helps identify the underlying issues causing bounces, enabling targeted solutions for list hygiene and deliverability improvement.

Email marketer from Gmass shares that regularly cleaning your email list by removing bounced addresses is crucial for maintaining a good sender reputation and improving email deliverability rates.

Email marketer from Email Geeks shares that raw codes make sense if you were the only one looking at them, but most of the rest of the world has no idea what they are looking at and they are a huge source of confused and angry users that blame your platform being broken for things that have nothing to do with their platform, and that raw codes are a huge customer service time sink with little upside to end users understanding and doing something useful with, and his company used to give raw codes and stopped doing that many years ago.

Email marketer from Email Geeks believes if an ESP isn’t managing delivery errors, he wouldn’t consider them an ESP.

Email marketer from Email Geeks explains that sending IP should be included, as it's not unheard of for sending IP to be outside of those listed in the SPF that ESP supplies.

Email marketer from HubSpot explains that monitoring bounce rates is essential for maintaining a healthy email list and sender reputation, positively impacting deliverability and campaign performance.

Email marketer from Email Geeks shares that some ESPs have a third category/or sub-category of _*certain*_ (and undocumented) SMTP 5xx responses.

Email marketer from EmailOnAcid explains that Monitoring bounce data can help identify potential spam traps. High bounce rates from unknown or invalid addresses may indicate a need to review list acquisition practices.

Email marketer from ActiveCampaign suggests segmenting recipients who consistently soft bounce, then reducing sending frequency or engagement campaigns to avoid future deliverability issues.

Email marketer from Email Geeks explains his company has an entire team that pours over DSN data to help clients become better senders by getting ahead of issues and are experienced in seeing certain patterns. He goes on to add that maybe people should add to their wish list for ESP's that the ESP actually monitors DSN data and takes action on it rather than just handing them a way to send mail then forgetting about them.

Email marketer from Campaign Monitor explains that using email list validation services before sending can identify and remove invalid or risky addresses, reducing bounce rates and protecting sender reputation.

Email marketer from Email Marketing Forum responds that Understanding specific ISP bounce policies allows tailoring email practices to meet their requirements, reducing bounce rates and improving deliverability.

Email marketer from Neil Patel Digital explains that a high bounce rate indicates problems with your email list or sending practices, negatively impacting sender reputation and deliverability.

Expert from Email Geeks responds that ESP bounce definitions have ZERO connection with reality.

Expert from Email Geeks explains that if she had a magic wand, she’d make ESPs actually give us useful bounce data, not just ‘hard’ and ‘soft’.

Expert from Email Geeks expresses frustration when clients want her to tell them what to do based on bounces and the bounces are “red” or “yellow”.

Expert from Email Geeks adds that the domain / MTA sending the bounce should also be included.

Expert from Email Geeks explains that there are services like Yahoo who have helpful but non standard TSS0* bounce codes.

Expert from Word to the Wise shares that actionable bounce data should include specific details about the reason for the failure (e.g., mailbox full, invalid user), the receiving domain, and relevant technical information for troubleshooting.

Expert from Email Geeks shares she's even in favor of the first 80 characters of the bounce message being included.

Expert from Spam Resource explains that understanding bounce message formats and SMTP error codes helps diagnose delivery issues and differentiate between temporary and permanent failures.

Documentation from SparkPost clarifies the distinction: bounces are permanent failures, while deferrals are temporary delivery delays which may eventually resolve. Monitoring both helps understand delivery patterns.

Documentation from Microsoft explains that Non-Delivery Reports (NDRs) provide detailed information about why an email could not be delivered, including the specific error code and a description of the problem.

Documentation from RFC 3464 explains that SMTP Enhanced Status Codes provide more granular information than standard SMTP codes, allowing for better diagnosis of delivery problems.

Documentation from Mailjet explains that a hard bounce indicates a permanent reason an email cannot be delivered (e.g., invalid address), while a soft bounce indicates a temporary issue (e.g., full inbox).

Documentation from AWS SES explains that using automated bounce processing via SNS notifications enables real-time identification of bounced email addresses and suppression list management.