Why am I getting a bounce when trying to push a SORBS delisting through?
Matthew Whittaker
Co-founder & CTO, Suped
Published 16 Apr 2025
Updated 16 Aug 2025
8 min read
It can be incredibly frustrating to receive a bounce message when you're trying to resolve an email deliverability issue, especially when you're attempting to get delisted from a prominent blocklist like SORBS. You've done the hard work of identifying the problem, and now the system itself seems to be blocking your efforts to communicate. A common bounce message encountered during this process is smtp;550 5.7.1 We do not allow automated responses to the Support System!. This specific error indicates that the SORBS support system has detected your incoming email as an automated response, which it is designed to reject.
This can feel like a Catch-22 situation, particularly if you are using a ticketing system or an email address that automatically generates replies or confirmations. The system's intent is to prevent email loops and manage the volume of requests, but it inadvertently creates a barrier for legitimate delisting attempts.
Understanding why this bounce occurs and how to navigate it is crucial for successfully getting your IP address removed from the SORBS blacklist (or blocklist). It requires a slight shift in your approach to communication, ensuring your request is perceived as a genuine, human interaction rather than an automated one.
The 550 5.7.1 We do not allow automated responses to the Support System! bounce is a specific rejection from the SORBS support system. It is designed to filter out emails that appear to be generated by automated systems, such as ticketing software, auto-responders, or system notifications. SORBS (Spamhaus Open Relay Blacklist System, though now independent of Spamhaus) generally aims to ensure that delisting requests come from a human who is actively managing the email server and understands the reason for the listing.
Example SORBS Bounce Message
smtp;550 5.7.1 We do not allow automated responses to the Support System!
When you send an email from a platform that automatically adds a ticket number to the subject line, includes a standard footer, or sends an immediate received confirmation, SORBS's filters can identify it as automated. This is intended to prevent endless loops of automated emails between two systems, which can consume significant resources and mask legitimate communication.
Additionally, SORBS (and other blocklists or blacklists) might employ techniques to fingerprint your sending mail transfer agent (MTA), IP address, or reverse DNS (rDNS) domain. If these indicators are associated with automated or suspicious activity, even a manually composed email might be rejected if it's sent from the same flagged environment.
Understanding the bounce message
The 550 5.7.1 status code means the mail system is not accepting your message. The accompanying text We do not allow automated responses to the Support System! specifically points to automated detection as the cause.
Ticketing System Issue: Your email, even if manually typed, is being sent via a system that adds identifying characteristics of an automated response, like specific headers or footers.
Auto-responder Trigger: The email address you are using for the delisting request has an auto-reply feature enabled, which SORBS's system is rejecting.
Overcoming SORBS delisting hurdles
Delisting from SORBS, or any email blacklist (also known as a blocklist), can be a complex process. Unlike some other blocklists that offer more streamlined removal procedures, SORBS is often perceived as having a less direct or more manual approach. This perception stems from their focus on ensuring the root cause of the listing has been adequately addressed before removal.
The core challenge lies in demonstrating that your IP or domain is no longer a source of unwanted mail. This isn't merely about sending a request, but about proving a change in behavior or configuration. If your IP was listed due to, for example, an open relay, a compromised account, or sending unsolicited bulk email, SORBS expects you to fix these underlying issues before any delisting is considered.
For a detailed guide on how to approach this, including ways to avoid paying for delisting, you can refer to our article on how to handle a SORBS listing. It's also worth understanding how severe a SORBS listing impact can be on your email deliverability, as this often motivates the urgency of delisting.
Automated ticketing system requests
Issue: Systems like Helpscout can append unique IDs or format messages in a way that flags them as automated.
Risk: Immediate bounce-back with the 550 5.7.1 error, preventing your request from reaching a human.
Perception: Seen as less personal, potentially indicating a lack of direct oversight for the listed IP.
Manual, personal email requests
Solution: Send your delisting request from a personal or organizational email account that does not have an auto-responder or is integrated into a ticketing system that modifies outgoing emails.
Benefit: Bypasses the automated rejection, increasing the likelihood of human review. This is crucial for navigating the delisting process from services like SORBS, as noted by Word to the Wise.
Perception: Signals genuine human interaction and direct involvement in resolving the issue.
Practical steps for a successful delisting request
The most effective way to address the automated response bounce from SORBS is to adjust your sending method. Instead of using a ticketing system or an email address with an auto-responder, craft your delisting request from a standard, personal email account. This ensures that the email appears to be a direct, human-initiated message.
When composing your request, be concise and provide all necessary information. Include the IP address in question, the specific SORBS list it's on (e.g., sbl.spamhaus.org or dul.dnsbl.sorbs.net), and a brief explanation of the actions you've taken to resolve the issue that led to the listing. Avoid overly technical jargon, but be specific about your remediation steps. Remember, the goal is to convince a human reviewer that your IP is now clean.
After sending your manual request, be patient. SORBS, like many blocklist providers, processes a high volume of requests. While they might not respond immediately, a clear, non-automated message significantly increases your chances of a successful review. For further assistance or discussion, some users have reported that SORBS may engage with inquiries on dedicated mailing lists, such as Mailop. Additionally, resources like the Folderly blog on SORBS can offer supplementary guidance.
It's also essential to be proactive. If you're dealing with an IP that's frequently listed (or blacklisted) on SORBS, review your sending practices. Are you sending to outdated lists? Is your server secured against open relays? Understanding what to do if your IP is blacklisted and preventing future listings is as important as the delisting itself.
Maintaining a clean sender reputation
Getting delisted is only half the battle, especially with a blocklist like SORBS (or blacklist) that monitors for re-offending behavior. To maintain a clean sender reputation and avoid future listings, consistent adherence to email best practices is critical. This involves both technical configurations and content-related practices.
Ensure your email authentication protocols like SPF, DKIM, and DMARC are correctly implemented and monitored. These records verify that your emails are legitimately from your domain, which builds trust with recipient mail servers and helps prevent spoofing that could lead to blocklisting. Regularly review your email sending logs for unusual activity or signs of compromise.
Furthermore, maintain pristine email lists by regularly cleaning out inactive or invalid addresses, and always ensure recipients have explicitly opted into receiving your communications. High bounce rates or complaints can signal poor list hygiene or unwanted content, leading to re-listing on blocklists. For more insights into common causes of bounces and how to troubleshoot them, explore our guide on why your emails are bouncing and how email blacklists actually work.
SORBS Listing Type
Common Causes
Initial Fixes
Spam
Sending unsolicited bulk email, high spam complaints.
Attempting to send mail from an IP address typically assigned to residential users (non-static).
Use a dedicated static IP address or a reputable transactional email service.
Views from the trenches
Best practices
Send delisting requests from a personal email address, not a ticketing system, to avoid automated rejection.
Clearly state the IP address and the specific SORBS list it's on in your delisting request.
Provide a concise explanation of the steps taken to fix the underlying issue that caused the listing.
Implement and monitor SPF, DKIM, and DMARC to maintain strong email authentication.
Regularly clean your email lists to remove inactive or invalid addresses to prevent high bounce rates.
Common pitfalls
Using automated ticketing systems or email addresses with auto-responders for delisting requests.
Failing to address the root cause of the SORBS listing before attempting delisting.
Sending multiple, identical delisting requests without modifying the approach, leading to repeated bounces.
Neglecting to monitor your IP address for re-listing on SORBS or other blacklists.
Having an insecure mail server (e.g., open relay) that can lead to repeated blacklisting.
Expert tips
Check the SORBS website for specific instructions or a dedicated delisting form, as processes can change.
If possible, try to understand if SORBS is fingerprinting your MTA or IP that might be causing the automated response.
Consider engaging with relevant email deliverability communities or forums for specific advice on tricky SORBS cases.
Document all steps taken to remediate the issue and include them in your manual delisting request.
Review your email sending patterns and data to ensure you're not inadvertently triggering spam traps or high complaint rates.
Marketer view
Marketer from Email Geeks says they tried re-wording and personalizing their delisting request, even asking how their week was, but still received the automated bounce.
July 19, 2023 - Email Geeks
Expert view
Expert from Email Geeks says SORBS might be fingerprinting the sender's MTA, IP, or rDNS domain, which could trigger the automated response.
Encountering a bounce when attempting to delist from SORBS (or any blocklist) can be a frustrating hurdle, but it's often a solvable problem rooted in the nature of your communication. The key takeaway is that SORBS's system is designed to reject automated responses, necessitating a manual, personal approach to your delisting request.
By sending your request from a personal email address, ensuring it's free of auto-replies or ticketing system signatures, and clearly articulating the steps you've taken to resolve the underlying issue, you significantly increase your chances of a successful delisting. Remember that consistent email hygiene, including proper authentication and list management, is paramount to staying off blocklists in the long run.
Spamhaus
0Spam
Cisco
NoSolicitado
URIBL
abuse.ro
ALPHANET
Anonmails
Ascams
BLOCKEDSERVERS
Calivent Networks
EFnet
JustSpam
Kempt.net
NordSpam
RV-SOFT Technology
Scientific Spam
Spamikaze
SpamRATS
SPFBL
Suomispam
System 5 Hosting
Team Cymru
Validity
www.blocklist.de Fail2Ban-Reporting Service
ZapBL
2stepback.dk
Fayntic Services
ORB UK
technoirc.org
TechTheft
Helpscout can append unique IDs or format messages in a way that flags them as automated.
