How do email marketers recover from deliverability issues?
Michael Ko
Co-founder & CEO, Suped
Published 5 Aug 2025
Updated 19 Aug 2025
6 min read
As an email marketer, few things are as frustrating as seeing your carefully crafted campaigns fall into the spam folder instead of reaching inboxes. Email deliverability issues can severely impact your marketing ROI, undermine trust with your audience, and even damage your brand reputation. When deliverability takes a hit, it often feels like an uphill battle to get back on track.
Recovering from these issues isn't a quick fix, but a strategic process that requires patience, analysis, and consistent effort. It involves a deep dive into what went wrong, a systematic approach to repair, and a commitment to best practices moving forward. Understanding the steps to diagnose, mitigate, and prevent future problems is crucial for any email marketer facing this challenge. The goal is not just to escape the spam folder temporarily but to build a robust and sustainable email program that consistently lands in the inbox.
Diagnosing the problem
The first step in any recovery process is to understand the root cause of the deliverability drop. Without accurately identifying what went wrong, any recovery efforts might be misdirected and ineffective. This diagnostic phase involves examining various technical and content-related factors that influence where your emails land.
Sender reputation: Start by checking your sender reputation with tools like Google Postmaster Tools or Microsoft SNDS. These provide insights into your IP and domain health, spam complaint rates, and authentication errors.
Key metrics: Analyze your bounce rates, spam complaint rates, unsubscribe rates, and engagement metrics (opens and clicks). A sudden spike in bounces or complaints, or a drop in engagement, indicates a problem. Understanding how to identify the cause is essential.
Blocklist status: Check if your sending IP or domain is listed on any major public blocklists (or blacklists). Being on a blocklist can immediately halt your email delivery. For more details, refer to our in-depth guide to email blocklists.
Authentication issues are a common culprit. Incorrectly configured SPF, DKIM, or DMARC records can lead to emails being flagged as suspicious or spam. Make sure these are set up correctly and aligned with your sending practices.
Rebuilding sender reputation
Once you have identified the likely causes, the next phase focuses on rebuilding your sender reputation and restoring trust with internet service providers (ISPs). This is often the most challenging part, as reputation is built over time through consistent, positive sending behavior.
Clean your lists: Remove unengaged subscribers, invalid addresses, and any known spam traps. Sending to a clean, active list is paramount. You can find out more about how to re-engage stale subscribers after issues.
Segment by engagement: For a period, only send to your most engaged subscribers. This helps send positive signals to ISPs. Gradually expand to less engaged segments as your reputation improves. This is sometimes referred to as rebuilding email trust.
Warm up your IP/domain: If you've had a significant issue, you might need to warm up your sending infrastructure by starting with small volumes to highly engaged users and slowly increasing volume and audience size.
Reaching out to ISPs is generally not recommended unless you are a very large sender with dedicated account managers. Most deliverability issues can be resolved by improving your sending practices rather than direct intervention. Focus on fixing the underlying problems on your end first.
Implementing a DMARC policy is critical for reputation. While a p=none policy allows you to monitor without affecting delivery, gradually moving to quarantine or reject shows ISPs you are serious about preventing abuse of your domain.
Optimizing content and engagement
The content of your emails and how you manage your campaigns play a significant role in deliverability. Even with perfect technical setup, poor content can trigger spam filters and lead to low engagement, both of which hurt your sender reputation. If your emails are still landing in spam, here's what you can do.
Review content for spam triggers: Avoid excessive capitalization, exclamation points, spammy phrases, and suspicious links or attachments. Use a healthy text-to-image ratio.
Personalization: Personalize your subject lines and content. This increases engagement, which is a positive signal to ISPs.
Encourage replies: Ask questions or encourage recipients to reply. Replies are strong positive signals.
Clear unsubscribe options: Make it easy for subscribers to opt out. Hidden unsubscribe links can lead to spam complaints, which are far more damaging.
Test your emails before sending. Send test emails to various inbox providers like Gmail, Outlook, and Yahoo to see where they land. This proactive step can catch issues before they affect your entire campaign.
Ongoing monitoring and prevention
Recovery isn't a one-time event, but an ongoing commitment to healthy email practices. Continuous monitoring and a proactive approach are key to maintaining good deliverability and preventing future issues.
Reactive approach
Waiting for deliverability to drop before taking action. Relying on customer complaints or low open rates to signal problems. Often results in prolonged recovery times and significant business impact.
Sporadic checks: Infrequent monitoring of sender reputation metrics and blocklist status. Being on a blacklist can severely impact your campaigns.
Outdated practices: Not adapting to new ISP requirements and filtering algorithms.
Proactive approach
Implementing consistent monitoring and preventative measures to identify and address potential issues before they escalate. Building a resilient email program that adapts to changes in the email ecosystem.
Regular monitoring: Continuously track your deliverability metrics, monitor Google Postmaster Tools, and check blocklists (or blacklists) daily.
Feedback loops (FBLs): Register for FBLs with major ISPs to receive notifications when recipients mark your emails as spam. This allows you to remove those users promptly.
Maintaining a clean and engaged list is arguably the most impactful preventative measure. Regularly removing inactive subscribers and invalid addresses ensures that your engagement metrics remain high and reduces the likelihood of hitting spam traps or generating complaints, which could lead to your sender reputation taking a hit.
Views from the trenches
Best practices
Maintain a clean and highly engaged email list by regularly removing inactive subscribers.
Consistently monitor your sender reputation using tools provided by major mailbox providers.
Ensure proper email authentication (SPF, DKIM, DMARC) is in place and correctly configured.
Segment your audience and tailor content to improve engagement and reduce complaint rates.
Common pitfalls
Sending to outdated or purchased email lists, which often contain spam traps and invalid addresses.
Ignoring negative engagement metrics like high bounce rates or spam complaints.
Not regularly checking for IP or domain blocklist (blacklist) listings.
Failing to implement or properly configure email authentication protocols.
Prioritize engagement over list size: a smaller, highly engaged list outperforms a large, inactive one.
Understand your audience: tailor content to their preferences to boost positive interactions.
Test your emails: send to various mailbox providers to check inbox placement before large sends.
Marketer view
Marketer from Email Geeks says they have been observing deliverability issues.
2019-02-13 - Email Geeks
Marketer view
Marketer from Email Geeks says that their usual protocol for recovering inbox placement, which involves sending only to recently engaged contacts, is not having the expected impact.
2019-02-13 - Email Geeks
The path to restored deliverability
Recovering from email deliverability issues is a multi-faceted process that spans technical configurations, audience management, and content strategy. It demands a systematic diagnostic approach, a commitment to rebuilding sender reputation through best practices, and continuous monitoring to prevent future setbacks.
By understanding the intricate factors that influence inbox placement and diligently applying the right strategies, email marketers can not only recover from deliverability challenges but also build a more resilient and effective email program. Consistency, patience, and a data-driven approach are your strongest allies on this journey.
Gmail, 
Outlook, and 
Yahoo to see where they land. This proactive step can catch issues before they affect your entire campaign.
