What should I do if Gmail blocks my email after using a purchased list?
Matthew Whittaker
Co-founder & CTO, Suped
Published 2 May 2025
Updated 16 Aug 2025
7 min read
Getting an email blocked by a major inbox provider like Gmail is a challenging situation, especially when it stems from using a purchased email list. I recently encountered this firsthand with a client whose emails were flat out blocked by Gmail following a significant increase in volume and spam complaints due to a purchased list. The error message received, 550-5.7.1 Our system has detected that this message is likely suspicious due to the very low reputation of the sending IP address. To best protect our users from spam, the message has been blocked., clearly indicated a severe reputation issue.
Unlike typical scenarios where emails might just land in spam folders, a direct block leaves no immediate path for deliverability, making recovery seem daunting. The immediate concern is how to resume email communication and rehabilitate a damaged sender reputation. This often involves a multi-pronged approach, focusing on diagnostics, immediate corrective actions, and a long-term strategy for rebuilding trust with inbox providers.
Understanding the block: Why it happened
The primary reason Gmail would outright block your emails is a severe and rapid degradation of your sender reputation. This often happens after sending to a purchased email list, which is almost always a bad idea for email deliverability. Purchased lists are notorious for containing a high percentage of invalid, unengaged, or spam trap addresses. When you send to such a list, you're essentially telling Gmail's algorithms that your sending practices are questionable, leading to spikes in spam complaints and bounces.
A sudden, large increase in sending volume to a low-quality list exacerbates the problem. Gmail's systems are designed to detect such anomalies as potential spamming behavior. High complaint rates (e.g., above 0.3%) and low engagement (opens, clicks) signal to Gmail that recipients do not want your emails. This negative feedback loop quickly diminishes both your IP and domain reputation, leading to blocklists (or blacklists) and delivery failures.
While it might seem arbitrary when the block occurs, it's typically the culmination of sustained poor sending practices, even if the purchased list was introduced weeks or months prior. The system might have been initially routing emails to spam, but once a critical threshold of trust is lost, a complete block is implemented to protect recipients. It's crucial to understand that buying email lists carries significant risks to your sender reputation, including ending up on a blacklist or blocklist.
Immediate corrective actions
The first, and most critical, step is to immediately halt all email sending to Gmail and Google Workspace recipients. Continuing to send will only worsen your reputation and prolong the block. A rest period of at least 7 days, ideally 15-30 days, is recommended to allow Gmail's systems to reset and for the block to potentially fall off. This period provides an opportunity to reassess and implement corrective measures without further damaging your sender reputation.
Next, you must completely remove the purchased list. Trying to clean it is futile; these lists are inherently problematic and will continue to attract spam complaints and hit spam traps. Focus on your legitimate, opted-in list, and ensure it undergoes thorough hygiene. During the rest period, it's also advisable to submit a ticket to Gmail Postmaster Tools, explaining the situation and the steps you are taking. While they may not respond directly, they do review tickets, and it can contribute to the eventual resolution.
The danger of purchased lists
It’s a common misconception that a purchased list can be cleaned or redeemed. The reality is that these lists are often generated through unethical means and are riddled with issues. Attempting to filter or recover deliverability from them will likely lead to further blocklisting and a prolonged impact on your sender reputation. Cut your losses immediately.
Rebuilding sender reputation
Once the initial rest period is over, the journey to rebuild your sender reputation begins. This is a long process that requires patience and adherence to best practices, typically taking 6 to 9 months for a full recovery with Gmail. Start by sending only to a very small segment of your most engaged, legitimate subscribers. Begin with extremely low volumes, perhaps 10-20 emails per hour for several days, and gradually increase if you see positive engagement and no blocks. This rewarming process is critical for demonstrating good sending habits to Gmail.
Ensure your email authentication records, specifically SPF, DKIM, and DMARC, are correctly configured. These protocols verify that your emails are legitimate and prevent spoofing, which significantly boosts your domain reputation with Gmail. A proper DMARC policy, even starting with p=none, provides valuable insights into your email stream.
Monitor your sender reputation closely using tools like Google Postmaster Tools. Pay attention to your spam rate, IP and domain reputation, and authentication status. Regularly cleaning your list to remove unengaged subscribers and invalid addresses will help prevent hitting spam traps and reduce bounce rates. Consider implementing a double opt-in process for all new subscribers to ensure high-quality, engaged contacts.
Before purchased list
Engagement rates: Consistent opens and clicks, low unsubscribe rates.
Spam complaints: Minimal, ideally below 0.1%.
Bounce rates: Low, indicating a clean list with valid addresses.
Deliverability: Most emails reaching the inbox, good sender reputation.
After purchased list
Engagement rates: Significant drop, low or non-existent opens and clicks.
Spam complaints: Sharp increase, potentially peaking at 5% or higher.
Bounce rates: High, indicating many invalid or nonexistent email addresses.
Deliverability: Emails blocked or consistently landing in spam, low IP reputation.
Preventing future blocks
To prevent future blocks (blacklists), the most important step is to commit to building and maintaining a healthy, engaged email list. This means focusing on organic growth through opt-in forms and avoiding the temptation of purchased or rented lists. Regularly segment your audience and send relevant, valuable content to foster engagement. A proactive approach to list hygiene and engagement is the cornerstone of good deliverability.
Continuous monitoring of your email program is also essential. This includes regularly checking your IP and domain against major blocklists, tracking engagement metrics, and paying close attention to spam complaint rates. Implement clear and easy unsubscribe options, and process them promptly. The easier it is for recipients to opt-out, the less likely they are to mark your emails as spam.
Finally, ensure your email content is relevant, concise, and avoids spam trigger words or overly image-heavy designs. Personalization and a clear call to action can boost engagement and positively influence your sender reputation. By prioritizing recipient experience and adhering to email best practices, you can build a robust sending reputation that withstands scrutiny from inbox providers like Gmail.
Metric
Target (Approximate)
Why it matters
Spam complaint rate
< 0.1%
High complaints severely damage reputation and lead to blocklists.
Hard bounce rate
< 2%
Indicates invalid addresses, signaling poor list hygiene.
Unsubscribe rate
< 0.5%
High unsubscribes can point to irrelevant content or high frequency.
Open rate
Industry dependent, but strong engagement is key.
Shows recipients value your emails and are engaging.
Views from the trenches
Best practices
Immediately stop sending to all Gmail and Google Workspace recipients for at least 7-15 days.
Completely discard any purchased or rented email lists; do not attempt to clean them.
Submit a ticket to Gmail Postmaster Tools, providing details of the issue and your corrective actions.
After the rest period, start email volume with a very small segment of highly engaged, legitimate subscribers.
Warm up your sending volume very slowly and steadily, increasing by small increments.
Common pitfalls
Continuing to send emails after a block, which further damages sender reputation.
Attempting to 'clean' a purchased list instead of discarding it entirely.
Switching IP addresses or sending domains too quickly without addressing the underlying reputation issues.
Increasing sending volume too rapidly during the rewarming process.
Neglecting to monitor Gmail Postmaster Tools or other deliverability metrics.
Expert tips
Focus on nurturing a truly opted-in and engaged email list for sustainable deliverability.
Implement double opt-in for all new subscribers to ensure high-quality contacts.
Regularly segment your list and send targeted content to maximize engagement.
Proactively monitor your IP and domain reputation to catch issues early.
Understand that full reputation recovery with Gmail can take several months of consistent, good sending.
Expert view
Expert from Email Geeks says they would not swap out the IP or domain at this point. They advise opening a ticket with Google Postmasters, even if they do not respond directly, as they do read tickets and can take action. It is essential to stop sending to Gmail and Google Workspace for at least 7 days.
2021-07-01 - Email Geeks
Marketer view
Marketer from Email Geeks says they have seen similar scenarios, often related to the website being infected by malware. They recommend checking the website and ensuring the domain passes Google Safe Browsing; if it does, the block often lifts on its own very soon.
2021-07-02 - Email Geeks
The path forward: Recovering and thriving
Facing a Gmail block due to a purchased list is a serious deliverability challenge, but it is recoverable. The key is to address the root cause, which is poor list quality and a damaged sender reputation. This means immediately ceasing sends to the problematic list, taking a necessary rest period, and then meticulously rebuilding trust with Gmail.
The recovery process is not quick, requiring patience and a disciplined approach to list hygiene, email authentication, and gradual rewarming. By committing to these best practices, you can eventually restore your email deliverability and ensure your messages reach the inbox, avoiding future blocklists (or blacklists) and maximizing the effectiveness of your email program.
