What is the impact of being listed on Spamrl blacklist when using a shared IP pool from MarketingCloud?
Matthew Whittaker
Co-founder & CTO, Suped
Published 15 Apr 2025
Updated 18 Aug 2025
8 min read
A client using MarketingCloud's shared IP pool recently encountered an issue where their emails were being rejected due to a listing on the Spamrl blacklist. This immediately raises concerns about deliverability, especially when operating on a shared infrastructure. Understanding the nature of Spamrl and the implications of such a listing within a shared environment is crucial for maintaining email outreach.
Shared IP pools are common for senders with lower volumes, offering cost efficiency and simplified management. However, they come with a significant caveat: your sender reputation is intertwined with that of other users on the same IP. This interdependence means that the poor sending practices of one user can negatively affect everyone else sharing that IP address.
The specific rejection message my client received was critical: "5.0.0 (undefined status) The sending IP (13.111.19.67) is listed on https://spamrl.com as a source of phishing." This clear statement pointed directly to Spamrl and highlighted a phishing concern, even though my client's own sending was legitimate. This highlights the collateral damage possible on shared IPs.
When a shared IP, especially one managed by a major platform like MarketingCloud, appears on a blacklist (or blocklist) like Spamrl, it can create a ripple effect impacting your email campaigns. The challenge then becomes diagnosing the root cause and navigating the limited options available to resolve the issue when you don't control the IP.
Email rejection message
5.0.0 (undefined status) The sending IP (13.111.19.67) is listed on https://spamrl.com as a source of phishing.
Spamrl is a lesser-known but still relevant blacklist (or blocklist) that primarily operates based on spamtrap hits and reported phishing attempts. Unlike some of the larger, more authoritative blacklists, its impact isn't universally felt across all mailbox providers. However, its listings can still cause significant deliverability issues, particularly with smaller to mid-tier European email providers and various shared hosting services.
The rejection message often provides clues, such as "The sending IP is listed on Spamrl as a source of phishing." This direct feedback indicates that the blocklist has identified malicious or unauthorized activity originating from the IP. While your specific campaigns might be legitimate, the shared nature of the IP means you bear the consequences of others' actions.
If your organization uses MarketingCloud's shared IP pool, a Spamrl listing directly implies that other senders on that same IP are engaging in practices that trigger spam traps or phishing alerts. This underscores a fundamental challenge with shared IPs: you inherit the collective reputation of all users. It's also important to ensure your own authentication records, such as SPF, DKIM, and DMARC, are correctly configured, as proper authentication helps build a robust sender identity. For more on the effect of shared IP pools and sending domains on email sender reputation, consider reading about how shared IP pools impact sender reputation.
Blacklist
Primary trigger
Impact level
Typical usage
Spamrl
Spamtrap hits, phishing
Low-medium (mid-low end European providers, shared hosts)
Using a shared IP pool from an email service provider (ESP) like MarketingCloud means you share IP addresses with many other clients. While this offers cost benefits, it also means your deliverability is directly influenced by the aggregate sending behavior of everyone else on that pool. Even if your sending practices are impeccable, a single problematic sender can lead to the entire IP address, and thus your emails, being blocklisted. For more details on how dedicated versus shared IPs affect deliverability, you might find this article on dedicated versus shared IP useful.
When an IP from a shared pool is blacklisted, it often results in "block bounces," meaning your emails are outright rejected by the receiving server. This directly impacts your reach and can lead to lost engagement and missed opportunities. This issue is particularly pronounced for MarketingCloud shared IPs, as their policy often notes that senders with lower volumes might struggle to maintain a strong sending reputation, relying heavily on the dominant high-volume senders. For more information on Salesforce Marketing Cloud's shared IP use policy, refer to their official documentation.
The shared nature of these IPs means that if phishing attempts or other abusive practices originate from any client on the pool, all clients might suffer, as seen with Spamrl. The burden then falls on the ESP to manage the shared pool's reputation and address the problematic senders. For more on what happens when your IP gets blocklisted (or blacklisted), refer to this guide on IP blocklisting impact.
Shared IP pool
Shared IP pools provide an economical option for senders, but their reputation is a collective sum. If one sender on the pool abuses it, everyone suffers. This often leads to unpredictable deliverability.
Cost efficiency: Generally lower cost due to shared infrastructure.
Reputation risk: Reputation is shared, making it vulnerable to other senders.
Limited control: No direct control over IP reputation or delisting processes.
Volume suitability: Best for lower sending volumes that don't need dedicated warming.
Dedicated IP address
A dedicated IP offers complete control over your sending reputation, allowing you to build and maintain trust with mailbox providers based solely on your own sending practices.
Higher cost: More expensive, as it's exclusively yours.
Full control: Direct ownership of IP reputation.
Predictable deliverability: With good practices, leads to consistent inbox placement.
The first step when facing a Spamrl blacklist notification on a shared MarketingCloud IP is to contact MarketingCloud support immediately. Since you do not own or directly manage the IP, the responsibility for delisting and managing the IP's reputation lies with them. Provide them with the exact rejection messages and any other relevant details you have gathered.
While waiting for your ESP to act, it's wise to consider alternative strategies. If the deliverability issues persist or significantly impact your campaigns, exploring the option of switching to a different shared IP pool, or even upgrading to a dedicated IP address, might be necessary. A dedicated IP provides exclusive control over your sending reputation, though it comes with its own responsibilities for maintaining good sending hygiene.
Internally, ensure that your email lists are clean, practices are compliant, and authentication protocols (SPF, DKIM, DMARC) are perfectly configured for your sending domains. Regularly monitoring your email deliverability metrics and keeping an eye on your IP and domain's standing on various blocklists (or blacklists) is essential. Tools that allow for blocklist monitoring can help you detect these issues early, before they severely impact your campaigns.
What to do when your shared IP is blocklisted
Contact ESP support: Immediately reach out to MarketingCloud (or your ESP) with rejection details. They manage the IP.
Review own practices: Double-check your email lists for quality and ensure all authentication (SPF, DKIM, DMARC) is correctly set up for your sending domains.
Monitor deliverability: Continuously track your inbox placement and bounce rates to assess the ongoing impact of the blacklist.
Consider alternatives: Discuss options like switching to a different shared IP pool or migrating to a dedicated IP address with your ESP.
The role of MarketingCloud and long-term considerations
For ESPs like MarketingCloud, managing shared IP pools means constantly monitoring and mitigating the actions of all clients to maintain a healthy sending reputation. If a pool consistently suffers from blocklistings (or blacklistings), it reflects poorly on their service and can lead to customer churn. Therefore, they have a vested interest in resolving these issues.
If MarketingCloud's efforts to remediate the Spamrl listing on the affected IP pool are insufficient, or if the problem recurs, it indicates a deeper issue within that specific shared environment. Persistent problems suggest that the ESP may not be effectively managing the quality of senders within that pool, or their compliance handling is lacking. For common issues with shared IP reputation for MarketingCloud users, you might find this guide on what to do when SFMC shared IP reputation tanks useful.
In the long term, if your sending volume justifies it, a dedicated IP offers greater control and stability. While it requires careful warming up and consistent good sending practices, it insulates your reputation from the actions of other senders. This strategic move can provide more predictable deliverability and reduce reliance on an ESP's shared pool management.
Conclusion
Navigating a Spamrl blacklist (or blocklist) listing while on a MarketingCloud shared IP pool can be frustrating due to the lack of direct control over the IP. The impact, while not global like major blacklists, can still significantly hinder deliverability to certain providers, particularly in Europe and with smaller hosts.
The key takeaway is that shared IPs mean shared responsibility and shared consequences. While you maintain stellar sending practices, others' missteps can affect your campaigns. Proactive communication with your ESP and internal diligence are your primary tools.
Ultimately, sustained issues might prompt a strategic decision: remain on a managed shared IP pool with ongoing vigilance, seek a different shared pool, or invest in a dedicated IP address to gain full control over your sender reputation.
Views from the trenches
Best practices
Regularly clean your email lists to remove inactive or problematic addresses.
Ensure all email authentication protocols are correctly configured for your domains.
Monitor your sender reputation on various blacklists and with mailbox providers.
Segment your audience and tailor content to minimize spam complaints.
Implement a double opt-in process for all new subscribers.
Common pitfalls
Ignoring rejection messages or assuming they are isolated incidents.
Failing to communicate promptly with your ESP about deliverability issues.
Not understanding the specific implications of shared IP environments.
Overlooking the importance of email authentication for sender credibility.
Sending to old, unengaged lists that contain spam traps.
Expert tips
Leverage DMARC reports to identify authentication failures and sources of unauthenticated mail.
Consider a dedicated IP if email volume and deliverability consistency are critical to your business.
Actively engage with your ESP's deliverability team for persistent shared IP issues.
Review your email content and sending frequency to align with best practices and recipient expectations.
Educate your internal teams on proper email etiquette and campaign management.
Expert view
Expert from Email Geeks says Spamrl is spamtrap driven and not widely trusted, but rejection messages often signal significant volumes of unauthenticated mail from the IP.
2024-01-24 - Email Geeks
Expert view
Expert from Email Geeks says Spamrl is likely associated with SpamExperts or AntiSpamCloud, which can lead to more impact at mid-to-low end European providers and shared hosting services.
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
If your organization uses MarketingCloud's shared IP pool, a Spamrl listing directly implies that other senders on that same IP are engaging in practices that trigger spam traps or phishing alerts. This underscores a fundamental challenge with shared IPs: you inherit the collective reputation of all users. It's also important to ensure your own authentication records, such as SPF, DKIM, and DMARC, are correctly configured, as proper authentication helps build a robust sender identity. For more on the effect of shared IP pools and sending domains on email sender reputation, consider reading about how shared IP pools impact sender reputation.
Spamhaus
