An email deliverability crisis rarely announces itself clearly. Open rates drop a few points, which could be a bad subject line. Gmail placement falls, which could be a one-off. Then it keeps happening.
By the time most eCommerce senders recognise they have a crisis, the underlying reputation damage has been compounding for weeks. The reason: the default tools, ESP dashboards and open rate reports, don’t show you what’s actually happening at the inbox level. Your Klaviyo dashboard might show 98% delivered and a 25% open rate while 40% of your Gmail sends are landing in spam.
This guide is the recovery process. Not prevention theory. What to do, in order, once you know something is wrong.
Step 1: Confirm You Have a Crisis and Define the Scope
Before changing anything, get accurate data on what is actually happening. Two tools are non-negotiable.
Google Postmaster Tools shows you how Gmail sees your sending domain. Log in and check your domain reputation: High, Medium, Low, or Bad. Also check your spam rate, which is the percentage of Gmail recipients who marked your mail as spam. A ‘Low’ or ‘Bad’ rating means Gmail is actively filtering your mail into spam. A spam rate above 0.10% means the same. Postmaster Tools is the only place you can see these numbers for Gmail specifically. Your ESP dashboard does not have this data.
Inbox placement monitoring tells you the actual placement percentages: what share of sends to Gmail, Yahoo, and AOL landed in the inbox versus spam. InboxEagle shows this per campaign, alongside the authentication results and sending IP for that send, so you can cross-reference when the problem started and what changed.
These two tools together tell you: how bad is it, which providers are affected, and when did it start. Without both, you’re guessing at the root cause.
Step 2: Identify the Root Cause
Once you have accurate placement and reputation data, the next question is why. The most common root causes, and how to confirm each:
High spam complaint rate. Check Postmaster Tools. If your spam rate is above 0.10%, this is the primary driver of Gmail reputation damage. The usual trigger is a campaign sent to a segment with low recent engagement, a re-engagement or winback sequence, or a welcome series that continued past the initial email to subscribers who never opened.
Blacklist listing. Run your sending domain and IP through MXToolbox. A listing on Spamhaus, Barracuda, or SORBS can block delivery at providers that query those lists. The blacklist entry itself shows the listing date and reason, which gives you the root cause. For the full removal process for each major blacklist, see the email blacklist removal guide.
Authentication failure. Check the authentication results in your campaign monitoring data. SPF, DKIM, or DMARC failures on live sends will show up campaign by campaign in InboxEagle’s Deliverability view. A new custom sending domain, a recent ESP switch, or a DNS misconfiguration can all cause this.
Sudden volume spike. If you sent a significantly larger campaign than usual to a cold or broad segment, the spike signals to mailbox providers that your sending pattern has changed. Combined with lower engagement signals from a colder audience, this drives reputation down quickly.
Most crises involve more than one factor. A volume spike often happens alongside elevated complaints because the spike reaches more disengaged subscribers. Fix the root cause first, then work through any secondary factors.
Step 3: Stop the Bleeding
While you’re diagnosing, take these actions immediately.
Pause all sends to disengaged subscribers. Define engaged as clicked in the last 30 days. Do not send to anyone outside that segment until you’re in recovery mode. Every send to a disengaged address right now is adding more negative signals to a domain reputation that is already damaged.
Suppress recent complainers. Pull any addresses who generated a spam complaint in the last 30 days and add them to your suppression list permanently. Klaviyo auto-suppresses on unsubscribes but complaint-based suppression depends on your feedback loop setup.
Hold high-risk sends. Pause any re-engagement campaigns, winback sequences, or sunset flows currently active. These target cold addresses by design and are exactly the wrong sends to continue during a crisis.
Don’t change your sending domain or ESP. A crisis is not the time to switch infrastructure. Moving to a new domain or IP during active reputation damage doesn’t reset your problem; it starts a new warm-up period while the original domain is still damaged.
Step 4: Resolve the Root Cause
For authentication failures: Fix the DNS records for SPF, DKIM, and DMARC. Use your domain registrar or DNS provider to verify the records are publishing correctly. Authentication fixes take effect within 24-72 hours of the DNS change propagating. InboxEagle will show passing authentication on the next send once it’s correct.
For blacklist listings: Identify the specific list and listing reason through the blacklist operator’s lookup page. Fix the underlying behavior that caused the listing: clean the addresses that generated spam trap hits, reduce complaint rate, or resolve the authentication issue. Only submit a delisting request after the fix is complete. Submitting before you’ve fixed the root cause almost always results in re-listing within days.
For high complaint rates: The fix is segmentation. Send only to subscribers who clicked in the last 30 days for the next 2-3 weeks. Review any flows that might be sending to cold segments and pause them. Check whether your list-unsubscribe header is correctly configured so recipients can unsubscribe easily rather than hitting the spam button.
For volume spikes: The fix is time and reduced volume. Send consistently to your engaged segment at moderate frequency (2-3 times per week maximum) for 3-4 weeks. Do not try to send your way out of a reputation problem with high frequency.
Step 5: The Recovery Sending Plan
Once the root cause is addressed, the recovery plan follows a specific pattern. The goal is to rebuild positive engagement signals with mailbox providers while avoiding any new negative signals.
Weeks 1-2: Send to your 30-day engaged segment only. These are subscribers who clicked in the last 30 days, your highest-engagement audience. Send 2-3 times per week with your best-performing content types: product updates, relevant promotions with clear value, useful content. Monitor Postmaster Tools and InboxEagle placement daily.
Weeks 3-4: If Postmaster Tools shows your domain reputation has moved from ‘Low’ to ‘Medium’, and InboxEagle placement at Gmail has improved, expand to your 60-day engaged segment. Continue monitoring. Do not expand if reputation hasn’t improved.
Weeks 5-8: Gradual expansion to your 90-day engaged segment, then 120-day. Each expansion happens only after stable placement results at the current segment. This is the same logic as domain warming, because you’re essentially re-establishing trust with mailbox providers from a lower starting point.
The recovery timeline is 3-6 weeks for spam complaint rate damage, measured from when you started clean sending to when Postmaster Tools shows ‘High’ reputation. Rushing the expansion is the single most common mistake, pushing the timeline out by weeks.
Step 6: Confirm Recovery Before Returning to Normal
Don’t declare recovery based on a single good campaign. The signals to confirm genuine recovery:
Postmaster Tools domain reputation is back to ‘High’ and has been stable there for at least one week.
Spam rate in Postmaster Tools is below 0.05% (well below the 0.10% threshold) across multiple recent sends.
Inbox placement in InboxEagle is back to your pre-crisis baseline at Gmail, Yahoo, and AOL across at least three consecutive campaigns.
Authentication is passing on every send: SPF, DKIM, and DMARC all showing pass in the campaign Deliverability view.
Once all four are holding, resume normal sending patterns gradually. Start by expanding to your 90-day engaged segment rather than jumping to your full list immediately. The full list should come back into rotation only after 4-6 weeks of stable post-recovery sending.
What Not to Do During a Crisis
A few common mistakes that extend recovery time significantly:
Sending more volume to “prove” you’re a legitimate sender. Mailbox providers don’t infer legitimacy from high volume. They infer it from positive engagement signals. Sending to disengaged addresses at high volume during a crisis is the opposite of what helps.
Switching to a new sending domain to escape the problem. Mailbox providers track both your old and new domains if you’re on the same IP pool. A domain switch without an IP change doesn’t help. A domain and IP change simultaneously just means you’re starting from zero reputation while your problem domain is still being watched.
Submitting blacklist delisting requests before fixing the root cause. Every blacklist operator explicitly states that premature requests result in re-listing. Fix the behavior, then request removal.
Using opens as the signal for recovery. Apple Mail Privacy Protection inflates open rates regardless of whether your emails are landing in the inbox. Check Postmaster Tools reputation and InboxEagle placement percentages, not your Klaviyo open rate dashboard.
How InboxEagle Fits Into Crisis Recovery
Two things InboxEagle gives you that are difficult to get any other way during a crisis:
First, per-campaign placement data. During recovery, you need to know whether each individual send is moving in the right direction or not. InboxEagle shows you the Gmail, Yahoo, and AOL placement percentage for every campaign, alongside the email performance score. You can see whether campaign 3 of your recovery sequence is better than campaign 1, or whether you’ve had a setback. Without placement data at this granularity, you’re reading tea leaves from open rates that Apple has partially corrupted.
Second, authentication correlation. When a campaign underperforms during recovery, InboxEagle’s Deliverability view shows whether authentication passed or failed on that specific send. If a DNS change wasn’t propagated correctly and DKIM failed on one campaign, you’ll see it in the same view as the placement drop, which means the diagnosis takes minutes rather than hours.
For monitoring Gmail domain reputation signals alongside your placement data, connecting Google Postmaster Tools to InboxEagle puts both in the same view. That combination covers the two most important signals during recovery: how Gmail rates your domain, and where your campaigns are actually landing.
Note: Content created with the help of AI and human-edited and fact-checked to avoid AI hallucinations.
