How to get SMTP bounce messages from Salesforce Marketing Cloud?
Michael Ko
Co-founder & CEO, Suped
Published 1 Jul 2025
Updated 19 Aug 2025
8 min read
Understanding why emails bounce is crucial for maintaining good sender reputation and optimizing email deliverability. Salesforce Marketing Cloud (SFMC) is a powerful platform, but navigating its bounce data can sometimes be challenging. When an email is sent, the recipient's mail server provides an SMTP (Simple Mail Transfer Protocol) response indicating whether the delivery was successful or if an issue occurred. These responses are what we refer to as bounce messages.
Bounce messages are essentially feedback from the recipient's mail server. They tell you precisely why an email couldn't be delivered. This information is vital for cleaning your email lists, improving campaign performance, and preventing your sending IP from landing on a blocklist (or blacklist). Ignoring these messages can lead to severe deliverability issues over time, including emails going to spam or being outright rejected by internet service providers (ISPs).
For email marketers and deliverability professionals, accessing and interpreting these SMTP bounce messages from SFMC is a key step in a robust email strategy. It allows for proactive list hygiene and targeted troubleshooting. I'll explain how to access this valuable data and what to do with it to ensure your messages reach the inbox.
Accessing Salesforce Marketing Cloud bounce data
Salesforce Marketing Cloud provides several ways to access bounce data, primarily through its built-in data views and reporting features. The most direct method for technical users is querying the _Bounce data view within Automation Studio. This data view contains detailed information about every bounce event that occurs, including the SMTP bounce code and reason, which are crucial for diagnostics. The data is typically retained for six months, offering a decent historical perspective for analysis.
To extract this data, you'll need to set up an SQL Query Activity in Automation Studio. This allows you to pull specific fields from the _Bounce data view and push it into a Data Extension for further analysis or export. You can tailor your query to include relevant fields like JobID, ListID, SubscriberKey, EventDate, IsUnique, BounceCategoryID, BounceTypeID, SMTPBounceReason, and SMTPStatusCode. These fields collectively provide a comprehensive view of why an email bounced.
For a comprehensive list of all fields available in the _Bounce data view, you can refer to the official Salesforce Marketing Cloud documentation. This resource details each field's purpose, helping you craft more effective queries to meet your specific deliverability monitoring needs.
Methods for extracting bounce messages
Once you have your SQL Query Activity set up, you can execute it manually as a one-off job or integrate it into a scheduled automation. For ad-hoc investigations, running it manually allows you to quickly retrieve bounce data for specific sends by changing the JobID. For ongoing monitoring, I recommend creating a daily automation that pulls recent bounce data into a dedicated Data Extension. This approach ensures you always have up-to-date bounce information readily available for analysis.
Example SQL query for retrieving bounce dataSQL
SELECT
b.SubscriberKey,
b.EventDate,
b.IsUnique,
b.BounceTypeID,
b.BounceCategoryID,
b.SMTPBounceReason,
b.SMTPStatusCode,
s.EmailAddress as SubscriberEmail
FROM
_Bounce b WITH (NOLOCK)
JOIN
_Subscribers s WITH (NOLOCK) ON b.SubscriberID = s.SubscriberID
WHERE
b.JobID = 12345678 -- Replace with your JobID
AND b.EventDate > DATEADD(day, -7, GETDATE()) -- Last 7 days
Another powerful way to get bounce information, especially for a broader view or when diagnosing specific deliverability issues, is using a Tracking Extract. This feature allows you to export various types of data related to your sends, including detailed bounce events. When configuring a Tracking Extract, ensure you select the 'Bounce Extract' option to include the raw bounce responses from recipient servers.
For specific bounce reasons and deeper insights into low deliverability, the Salesforce Help article on pulling bounce reasons provides guidance. This often involves querying send data or running tracking reports to identify trends in your bounce data, which can point to larger issues like list quality or content problems that are triggering ISPs.
Extracting bounce data via API
For more programmatic access, SFMC's API allows you to retrieve bounce event details. This is particularly useful for integrating bounce data into external systems or custom dashboards. The Marketing Cloud APIs provide endpoints to pull detailed bounce events, allowing for automated processing and faster response to deliverability issues.
Interpreting SMTP bounce codes and types
Once you have the bounce data, understanding the SMTP codes and reasons is paramount. These codes provide specific details about why an email bounced. They are typically structured as three-digit numbers (e.g., 550, 421) followed by a human-readable message. Common categories include hard bounces (permanent failures) and soft bounces (temporary issues). Knowing the difference helps determine if you need to remove an address from your list or if it's a temporary network problem.
For a deeper dive into classifying and managing these codes, consider how email service providers classify SMTP bounce codes. This understanding can inform your bounce management strategy in SFMC. For example, a 550 code often indicates a non-existent recipient, warranting removal, while a 4xx code (like 421) might suggest a temporary server issue or mailbox full, which SFMC will typically retry.
Hard bounce vs. soft bounce
Salesforce Marketing Cloud automatically handles hard bounces by setting the subscriber status to Bounced and excluding them from future sends to protect your sender reputation. Soft bounces, being temporary, are retried a certain number of times before being converted to hard bounces if delivery consistently fails. You can find more information on how SFMC handles email bounces and bounce management best practices directly on our knowledge base.
Analyzing the SMTP bounce reasons (e.g., 'mailbox full', 'user unknown', 'spam content detected') and status codes will provide actionable insights. This data allows you to segment your audience, update your lists, and refine your sending practices. For example, if you see a spike in 550 bounces for 'user unknown', it highlights a need for better list validation. Understanding how to parse SMTP responses is a critical skill for any email marketer.
Hard bounces (permanent)
Definition: Indicates a permanent delivery failure, meaning the email address is invalid, non-existent, or blocked. SFMC automatically suppresses these addresses.
Examples: "User unknown", "Host unknown", "Domain not found".
Action: Immediately remove these email addresses from your active sending lists to avoid harming your sender reputation and to comply with ISP requirements.
Soft bounces (temporary)
Definition: Indicates a temporary delivery issue, often due to a full inbox, server downtime, or a temporary block. SFMC retries sending for a period.
Examples: "Mailbox full", "Temporarily unavailable", "Message too large".
Action: Monitor these. If they persist for a subscriber, they will convert to a hard bounce. Investigate recurring soft bounces for patterns.
Best practices for bounce management
Actively managing your bounce rates is a critical component of successful email marketing. High bounce rates signal to ISPs that you might be sending to invalid or unengaged addresses, which can lead to your emails being flagged as spam or your sending IPs being placed on a blacklist or blocklist. Implement robust list hygiene practices to mitigate this risk. You can also explore our guide on useful bounce data for email marketing to improve your approach.
A good practice is to periodically review your bounce categories and reasons to identify emerging trends. For instance, if you notice an increase in bounces related to specific domains, it might indicate a deliverability issue with that particular ISP. In such cases, you might need to investigate further by checking if your IPs are on a blocklist or adjusting your sending patterns. Regularly monitoring your email deliverability is key to staying ahead of potential issues.
Ultimately, proactive bounce management in SFMC isn't just about avoiding problems, it's about optimizing your email program for maximum engagement and return on investment. By understanding and acting on your bounce data, you can significantly enhance your email deliverability and ensure your messages consistently reach their intended recipients. You can also gain insight on boosting your email deliverability rates by implementing technical solutions from top performing senders.
Views from the trenches
Best practices
Regularly query the _Bounce data view in Automation Studio to identify problematic email addresses and domains.
Set up automated processes to move hard-bounced subscribers to a suppression list immediately to prevent future sends.
Segment your bounce data by campaign, time, and bounce type to pinpoint specific issues or trends in deliverability.
Utilize Tracking Extracts to get comprehensive bounce reports, which can be useful for external analysis or compliance.
Monitor SMTP status codes and bounce reasons to understand the root cause of delivery failures and adjust sending practices.
Common pitfalls
Neglecting to regularly clean your lists, which can lead to increased bounce rates and damage to sender reputation.
Not differentiating between hard and soft bounces, leading to unnecessary suppression or persistent sending to invalid addresses.
Relying solely on high-level bounce reports without digging into the raw SMTP bounce messages for detailed insights.
Ignoring recurring soft bounces, as these can eventually turn into hard bounces and negatively impact deliverability.
Not automating bounce data extraction, which can result in manual, time-consuming processes and delayed issue resolution.
Expert tips
Implement a consistent list validation process before sending campaigns, especially for older or acquired lists.
Configure alerts for sudden spikes in bounce rates to enable quick investigation and mitigation of issues.
Use bounce data to refine your audience segmentation and targeting, focusing on engaged subscribers.
If your IP is blocklisted (or blacklisted), ensure you understand the specific reasons for the listing and follow the delisting procedures.
Regularly review your email content for elements that might trigger spam filters, contributing to bounces.
Marketer view
A marketer from Email Geeks says they set up an automation to pull all bounce messages into a data extension, which they base on the job ID for specific campaigns.
2019-12-19 - Email Geeks
Marketer view
A marketer from Email Geeks advises that for specific domains, it's useful to add an 'AND Domain =' clause to your queries, as Data Extensions might only display a limited number of records without exporting.
2019-12-19 - Email Geeks
Summary
Accessing and analyzing SMTP bounce messages from Salesforce Marketing Cloud is a fundamental aspect of maintaining optimal email deliverability. By leveraging data views, SQL queries, and tracking extracts, you gain granular insight into why your emails are not reaching their intended recipients. This data empowers you to make informed decisions, whether it's cleaning your lists, adjusting content, or troubleshooting more complex issues.
Proactive bounce management helps protect your sender reputation, reduces the likelihood of landing on a blocklist, and ultimately ensures your email campaigns achieve their desired results. Integrating these practices into your regular workflow will lead to healthier email lists and more effective communications.
