My domain got blacklisted on Spamhaus. Here is how I recovered

blacklist_survivor · 2026-04-02 · 2,890 views

Two weeks ago I checked MXToolbox and found one of my best sending domains on the Spamhaus SBL. My stomach dropped. This domain had been running for 5 months with solid deliverability and suddenly it was blacklisted. Here is exactly what happened, what I did to recover, and what I changed to prevent it from happening again.

How I found out: Reply rates on one of my campaigns dropped from 3.8% to 0.4% over three days. I thought it was a copy issue at first. Tested new subject lines, rewrote the body, nothing helped. Then I ran a GlockApps test and inbox placement was at 12%. That is when I checked MXToolbox blacklist scanner and saw the Spamhaus SBL listing.

What caused it: After investigation, I am 90% sure it was a spam trap hit. I had imported a prospect list from a data source I had not used before without running it through ZeroBounce first. Lazy mistake. One of those emails was likely a recycled spam trap, which is an old email address that has been repurposed by Spamhaus to catch senders who email addresses without verification.

Step 1: Stop all sending immediately. I paused every campaign using that domain and its inboxes within 10 minutes of finding the listing. Continuing to send from a blacklisted domain makes things worse and can get your IP blacklisted too.

Step 2: Identify the cause. I reviewed my sending logs for the 72 hours before the listing appeared. Found the unverified list import. Deleted that entire prospect list from my sending platform.

Step 3: Submit a Spamhaus removal request. Spamhaus has a self-service removal tool at their website. I submitted the request, explained that I had identified the cause (unverified list with a probable spam trap), and described the steps I had taken to prevent recurrence. The form is straightforward. Do not lie or make excuses. Be honest about what happened.

Step 4: Wait. Spamhaus processed my removal request in 48 hours. Some people report faster turnarounds, some slower. During this period I did not send a single email from that domain. I left warmup running on the inboxes at very low volume (5 per day) just to keep them active.

Step 5: Rebuild slowly. After delisting, I did not immediately resume full volume. I started at 5 cold emails per inbox per day (down from my usual 18) and increased by 2-3 per day over 10 days. I monitored GlockApps placement daily during the ramp. Inbox placement climbed from 45% on day 1 post-delisting to 78% by day 10.

Step 6: Prevent recurrence. Three changes I made permanently. First, every single prospect list now goes through ZeroBounce before it touches my sending platform. No exceptions, no matter how trustworthy the data source seems. Second, I set up weekly MXToolbox monitoring alerts for all my sending domains so I catch blacklistings within hours instead of days. Third, I reduced per-inbox volume from 18 to 15 per day to give myself more margin.

Current status: Two weeks post-recovery, the domain is back to 82% inbox placement and climbing. Reply rates are at 3.1%, not quite back to the 3.8% pre-blacklisting level but trending in the right direction. Full reputation recovery takes 30-60 days in my experience.

The lesson is simple. Verify every list. Monitor your blacklist status. The 5 minutes it takes to run a list through ZeroBounce could save you 2-3 weeks of downtime and thousands in lost pipeline.