What to do when Gsuite IP is blacklisted on SORBS?
Matthew Whittaker
Co-founder & CTO, Suped
Published 21 Apr 2025
Updated 19 Aug 2025
7 min read
Discovering that a Google Workspace (formerly G Suite) IP address is blacklisted on SORBS can be a frustrating experience, especially when you are not directly responsible for the listing. It is a common issue for users of large email providers. Email providers like Google use shared IP addresses, meaning many different users send emails from the same range of IPs.
When a shared IP gets listed, it usually means someone else on that same IP pool has engaged in activities that triggered the blacklist. This can unfortunately impact your email deliverability, even if your own sending practices are impeccable. The challenge then becomes how to navigate this situation, given that you do not own the IP address in question.
The Spam and Open Relay Blocking System (SORBS) is a real-time blocklist (RBL) that lists IP addresses known for sending spam, operating as open relays, or exhibiting other questionable email behaviors. When an IP is listed on SORBS, mail servers configured to use this blocklist may reject or flag emails originating from that IP address, leading to deliverability issues for legitimate senders. An in-depth guide to email blocklists can provide further context on how these systems operate.
Google Workspace, like many large email service providers, operates on a massive scale, using pools of shared IP addresses to send emails. This pooling allows for efficient resource management but introduces a shared responsibility for IP reputation. If one sender on a shared IP exhibits poor sending habits, the entire IP can suffer, affecting all users on that IP.
When your Google Workspace IP is blacklisted on SORBS, it is almost certainly due to the actions of other users sharing that IP. The description or identifiers associated with the listing on SORBS will often not match your organization's sending patterns because the listing reflects the collective behavior of thousands of senders. This inherent nature of shared IPs means you cannot directly request a delisting from SORBS, as you do not own the IP address.
The challenge of shared IP blocklists
The primary challenge with a shared Google Workspace IP address being blocklisted on SORBS is the limited direct action you can take. While SORBS does offer a delisting process, it typically requires the IP owner (Google, in this case) to initiate it. Individual users attempting to delist an IP they do not own will likely face rejection, as SORBS is generally not receptive to such requests for shared resources.
While a SORBS listing can cause deliverability issues, particularly with receivers that heavily rely on it (like some instances of Proofpoint), it is generally considered to have a lower impact compared to other major blocklists such as Spamhaus. Your emails going to spam or being outright rejected might stem from a broader set of issues, not just a single SORBS entry.
This situation highlights the delicate balance of shared IP environments, where the actions of a few can impact many. Google actively monitors its IP reputation and works to mitigate these issues, but the rotation of IPs means that a blacklisted IP today might be replaced by a clean one tomorrow, and vice versa.
SORBS and shared IPs
It is important to understand that SORBS is owned by Proofpoint. While some mail servers may use SORBS data, its impact can vary. Direct delisting requests for shared IPs will often be declined, as only the IP owner can address the underlying issues leading to the listing.
Immediate and indirect actions
While you cannot directly delist a Google Workspace IP from SORBS, you can take several indirect actions to improve your email deliverability. The first step is to check if your IP is blacklisted by a general SORBS listing, even if it is a shared IP. Then, contacting Google Workspace support is crucial. They are the IP owners and are responsible for managing their network's reputation. While they may not provide real-time updates on specific IP delistings, they have internal processes to address blocklist issues.
You should also focus on optimizing your own sending practices within Google Workspace. This includes ensuring your emails are highly engaged with, avoiding sending to old or unengaged lists, and maintaining good sender reputation. Even on shared IPs, your domain's reputation, governed by factors like DMARC, SPF, and DKIM alignment, plays a significant role in deliverability. Poor domain reputation can cause emails to go to spam, regardless of the IP status. If your Gsuite IP is blacklisted, this advice is particularly relevant.
When you encounter bounce messages, especially from services like Mimecast, investigate them thoroughly. While a bounce might cite a blocklist, it could be a symptom of a broader issue with your sending practices or domain reputation. Addressing the root cause of these rejections is more effective than focusing solely on a SORBS listing that you cannot directly control.
Limited direct actions
No direct delisting: As a Google Workspace user, you do not own the IP address, so you cannot request delisting directly from SORBS.
Impact of others: Your deliverability can be affected by the poor sending practices of other users sharing the same IP pool.
Automated responses: Automated replies from blocklist administrators may seem unhelpful but reflect their standard policy for shared IPs.
Effective indirect actions
Contact Google Support: They are the only entity that can engage with SORBS for their IPs. Open a support ticket.
Monitor deliverability: Utilize Google Postmaster Tools to track your domain's reputation and identify trends.
Improve sending hygiene: Focus on engagement, list cleaning, and content quality to maintain a strong domain reputation.
Long-term deliverability strategy
Beyond addressing specific blacklist entries, a holistic approach to email deliverability is key. A SORBS listing on a shared IP is often a signal that there might be broader issues impacting your email program, or simply an unfortunate side effect of shared infrastructure. Focusing on robust authentication, like DMARC, SPF, and DKIM, is critical for demonstrating sender legitimacy.
Consistently monitoring your domain reputation and engagement metrics will help you detect underlying problems. If your sales team's emails are not reaching clients, or you are receiving rejection messages, it is essential to analyze the bounce codes and headers. These often provide specific reasons for rejection that can guide your troubleshooting efforts more effectively than a generic blacklist lookup.
In the long term, focusing on a strong sender reputation through consistent, desired communication is the most robust defense against deliverability challenges, regardless of temporary IP blacklist issues. This includes ensuring your email content is valuable, your subscriber lists are clean, and you are adhering to industry best practices.
Example Mimecast rejection message
554 Email rejected due to security policies - https://community.mimecast.com/docs/DOC-1369#554 [UNIQUE_HASH]
Views from the trenches
Best practices
Actively monitor all bounce messages, especially those from recipients using services like Mimecast or Proofpoint.
Utilize Google Postmaster Tools to gain insights into your domain's reputation and deliverability performance.
Ensure your email authentication (SPF, DKIM, DMARC) records are correctly configured and aligned.
Common pitfalls
Attempting to manually delist a Google Workspace IP from SORBS, which is often unsuccessful due to shared IP ownership.
Assuming a single blacklist listing is the sole cause of all deliverability issues without investigating broader symptoms.
Ignoring bounce messages or treating them as isolated incidents rather than indicators of systemic problems.
Expert tips
While SORBS might not be the highest impact blacklist, some organizations, like Proofpoint, do integrate its data, so it is worth monitoring.
Shared IP blacklistings are a common challenge with large email providers, requiring a focus on internal sending practices.
Focusing on overall email health and proper authentication will often mitigate the impact of shared IP issues.
Marketer view
Marketer from Email Geeks says they can't imagine a Google IP is dedicated to a single user account, implying it is almost certainly a shared IP.
2020-02-21 - Email Geeks
Expert view
Expert from Email Geeks says they would be highly skeptical that problems are directly related to a SORBS listing and that issues could be correlated but likely not causal.
2020-02-21 - Email Geeks
Summary
Dealing with a Google Workspace IP address blacklisted on SORBS can be challenging due to the shared nature of Google's sending infrastructure. Direct delisting by individual users is generally not feasible, as Google owns and manages these IPs. However, this does not mean you are powerless.
By focusing on improving your own sending practices, maintaining strong email authentication, and leveraging Google's support channels, you can mitigate the impact of such listings. Remember that a SORBS entry might be a symptom, not the root cause, of broader deliverability issues, so a holistic approach to email health is always the most effective strategy.
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Proofpoint. While some mail servers may use SORBS data, its impact can vary. Direct delisting requests for shared IPs will often be declined, as only the IP owner can address the underlying issues leading to the listing.
