How can I salvage my email domain and IP reputation after IT deleted the subdomain and caused high spam rates?
Michael Ko
Co-founder & CEO, Suped
Published 23 Jul 2025
Updated 19 Aug 2025
6 min read
Experiencing a sudden collapse in your email domain and IP reputation is a nightmare, especially when it stems from an unexpected event like a subdomain deletion. The impact can be immediate and severe, pushing your sender score to alarming lows and leading to high spam rates. Many businesses face the daunting task of recovering from such incidents, questioning if their email program can ever return to normal.
The good news is that while challenging, salvaging your email domain and IP reputation is absolutely possible. It requires a strategic, multi-faceted approach, addressing both the technical missteps and underlying sending practices that might have contributed to the problem. I've seen situations like this before, and with diligent effort, recovery is within reach.
Immediate damage control and DNS configuration
The first and most critical step is to halt all email sending from the affected domain. Continuing to send emails when your reputation is severely damaged will only dig you deeper into a hole, as mailbox providers (like Google and Microsoft) will aggressively filter your messages to the spam folder or reject them entirely. This pause provides a necessary breathing room for your reputation to begin its slow climb back, and for you to implement the required fixes.
Next, you must address the technical foundation that was disrupted. The deletion of a subdomain likely means that critical DNS records for email authentication, such as SPF, DKIM, and DMARC, were removed or invalidated. Without these, mailbox providers cannot verify that your emails are legitimate, flagging them as suspicious.
Immediate technical checklist
Re-establish subdomain: Work with your IT team to bring the subdomain back online.
Configure DNS records: Ensure your SPF, DKIM, and DMARC records are correctly set up for the restored subdomain. This is crucial for authentication.
Proactive monitoring: Implement a system for blocklist monitoring and DNS record checks to prevent future unexpected changes. DMARC reports are reactive, so proactive monitoring is key.
Below is an example of what an SPF record for your subdomain might look like. This particular example includes a broad range, which is often not recommended, but serves as an illustration. Always consult with your email service provider for the correct and most secure values.
Addressing high spam rates and authentication issues
The 25% spam complaint rate is a huge red flag. This indicates a serious problem with your email content, list quality, or sending practices. It's often compounded by the absence of an unsubscribe link, which forces recipients to mark emails as spam if they want to stop receiving them. This is why it is so important to distinguish between transactional and marketing emails.
Transactional emails
These are typically one-to-one communications related to a specific action, like order confirmations, password resets, or shipping notifications. They generally do not require an unsubscribe link, as they are essential for the user's interaction with your service.
Marketing emails
These are promotional, informational, or newsletter-type emails. By law (and best practice), they must include a clear and easy-to-use unsubscribe mechanism. Sending marketing emails without an unsubscribe option is a surefire way to escalate spam complaints and harm your reputation.
To address this, review all your email templates. Ensure that any email that could be perceived as marketing or bulk communication includes a visible and functional unsubscribe link. This simple change can significantly reduce your spam complaint rate. Additionally, thoroughly clean your email list by removing inactive or non-existent addresses to avoid spam traps, which are another major cause of reputation damage. Consider implementing a double opt-in process for new subscribers to ensure high engagement and valid addresses from the start.
If Gmail is blocking 98% of your emails, you'll need to use their Postmaster Tools. This resource provides valuable insights into your domain and IP reputation, spam rates, and other critical metrics. You can access the tools directly through the Google Admin Help Center. Pay close attention to the Spam Rate and Domain Reputation dashboards. There is also a specific Gmail mitigation form you can fill out after you've implemented all your fixes and started a proper warm-up process.
The gradual recovery: Re-warming your sending reputation
Once the technical foundations are restored and you've addressed internal policy issues like unsubscribe links, you can begin the critical process of warming up your domain and IP reputation. This must be done slowly and carefully. A sudden large volume of emails from a damaged reputation can trigger spam filters again.
Start by sending only to your most engaged subscribers, those who have recently opened or clicked your emails. This helps demonstrate positive engagement to mailbox providers, signaling that your emails are valued. Gradually increase your sending volume to this engaged segment. As your reputation improves, you can slowly expand your audience.
Gradual warm-up approach
Start small: Begin with a very low volume to highly engaged recipients.
Monitor closely: Use Google Postmaster Tools and other monitoring services to track your domain reputation and inbox placement rates.
Increase slowly: Only increase volume when you see consistent positive results.
Segment aggressively: Prioritize your most active segments to build trust first.
This re-warming process can take weeks, or even months, depending on the severity of the damage. Patience and consistency are crucial. Avoid any sudden spikes in email volume or content changes that could trigger new issues. You may find more detailed warm-up strategies in guides like how to re-warm a low volume email domain.
Long-term strategies and prevention
To prevent future incidents, establishing clear communication and processes with your IT team is vital. DNS record management should be a collaborative effort, with defined protocols for any changes to critical infrastructure. Proactive monitoring isn't just about DMARC reports, which are reactive. It's about real-time alerts if DNS records are altered or if your domain (or IP) appears on a major email blocklist (or blacklist).
Beyond technical fixes, continue to nurture a healthy sending environment. This includes regularly cleaning your email list, maintaining consistent sending volumes, personalizing content, and encouraging positive engagement (opens, clicks). These long-term practices contribute significantly to a strong and resilient sender reputation. Remember, reputation is built over time with consistent positive behavior and can be quickly lost with missteps.
Before the fix
Email sending from your domain was severely impacted, with high spam rates and blocked messages, due to critical DNS records for authentication being removed.
Reputation Score: Plummeted to critically low levels.
By pausing sends, reconfiguring DNS, and implementing strategic warm-up, your email performance gradually improves.
Reputation Score: Steadily increasing towards healthy levels.
Deliverability: Improved inbox placement and reduced spam complaints.
The path to recovery can be arduous, but it is achievable. Focus on systematically addressing each issue, prioritizing technical fixes, and then meticulously rebuilding your sending reputation through careful warming and consistent best practices. This layered approach is your best bet for getting your emails back into inboxes.
Views from the trenches
Best practices
Implement proactive DNS monitoring to detect changes to SPF, DKIM, and DMARC records immediately.
Always include a visible and easy-to-use unsubscribe link in all marketing and bulk emails.
Regularly clean your email list by removing inactive users and avoiding spam traps.
Segment your audience and prioritize sending to your most engaged subscribers during warm-up periods.
Maintain clear communication channels with your IT department regarding email infrastructure changes.
Common pitfalls
Continuing to send emails at high volume after a reputation hit, worsening the problem.
Neglecting to include unsubscribe links in marketing emails, leading to high spam complaints.
Failing to properly configure or monitor SPF, DKIM, and DMARC records.
Sending to unengaged or old email lists, which increases bounce rates and spam trap hits.
Expecting instant reputation recovery, as the process takes time and consistent effort.
Expert tips
If possible, pause all email sending initially to allow bad reputation to dissipate.
Leverage Google Postmaster Tools for in-depth insights into your Gmail sending reputation.
Consider using other communication channels like SMS for critical, time-sensitive messages.
Engage in a conservative and gradual email warm-up, increasing volume slowly over time.
Fill out the Gmail mitigation form after implementing fixes and beginning the warm-up process.
Expert view
Expert from Email Geeks says there is hope for recovery, but it requires fixing all underlying issues thoroughly.
2024-05-18 - Email Geeks
Expert view
Expert from Email Geeks says that this is not a situation for gradual changes, but rather to stop sending mail, fix everything to be perfectly clean, and then go to a conservative warm-up program.
2024-05-18 - Email Geeks
Reclaiming your email deliverability
The unfortunate deletion of a subdomain and subsequent high spam rates can feel like an insurmountable setback for your email program. However, by taking immediate, decisive action to pause sending, rectify your DNS configurations, and systematically re-warm your domain, you can indeed recover your email domain and IP reputation. Consistency, attention to detail in your sending practices, and proactive monitoring will be your greatest allies on this journey.
Remember, email deliverability is an ongoing effort that requires continuous vigilance and adaptation. By learning from this incident and implementing robust preventative measures, you can ensure the long-term health and effectiveness of your email communications.
Google and 
Microsoft) will aggressively filter your messages to the spam folder or reject them entirely. This pause provides a necessary breathing room for your reputation to begin its slow climb back, and for you to implement the required fixes.
Gmail is blocking 98% of your emails, you'll need to use their Postmaster Tools. This resource provides valuable insights into your domain and IP reputation, spam rates, and other critical metrics. You can access the tools directly through the Google Admin Help Center. Pay close attention to the Spam Rate and Domain Reputation dashboards. There is also a specific Gmail mitigation form you can fill out after you've implemented all your fixes and started a proper warm-up process.
