How Do I Know If My Email Domain Is Burned?

A burned domain shows these signs: bounce rates above 3%, emails consistently landing in spam, Google Postmaster showing LOW or BAD reputation, blacklisted on Spamhaus or Barracuda, and open/reply rates near zero despite good copy. If you see 3 or more of these, the domain is likely burned and you need to decide between recovery and replacement.

“Burned” is not a technical classification — it is an operational reality. A burned domain is one where ISPs have decided that emails from your domain are unwanted, and they are routing them to spam or rejecting them outright. There is no single threshold that defines “burned.” Instead, it is a constellation of signals that together indicate your domain reputation has degraded beyond the point where normal sending is effective. Here are the 7 signs to watch for.

1. Bounce rate above 3%

A healthy cold email domain maintains bounce rates below 2%. Between 2-3% is a warning zone. Above 3% sustained over multiple sends is a strong indicator of domain damage. At 5%+, damage is almost certainly severe.

Check your bounce rate in your sending platform (Smartlead, Instantly) and calculate it as: (bounced emails / total sent) x 100. Look at the trend, not just the current number. A domain with 1.5% bounce rate that has been climbing by 0.3% per week is heading toward burnout even though it has not crossed 3% yet.

What to do: Stop sending from this domain immediately. Investigate the bounce causes — are they hard bounces (invalid addresses) or soft bounces (reputation-based rejections)? Hard bounces indicate a list quality problem. Soft bounces indicate the domain is already being flagged by ISPs.

2. All emails going to spam

If your emails are consistently landing in spam across multiple recipients and ISPs, the domain reputation is the likely culprit. Test this by sending to seed accounts at Gmail, Outlook, and Yahoo. If the email lands in spam at all three, the problem is domain-level, not content-level.

Be specific about the pattern. If emails land in spam only at Gmail but inbox at Outlook, the problem may be Gmail-specific reputation (check Postmaster Tools) rather than a fully burned domain. If spam placement is universal across providers, the domain is burned. You can also use inbox placement tools like GlockApps to test placement across dozens of seed addresses.

What to do: Send test emails to personal accounts at different providers. If spam placement is across Gmail, Outlook, and Yahoo, the domain is burned. If it is limited to one provider, focus recovery efforts on that specific reputation system.

3. Google Postmaster shows LOW or BAD reputation

Google Postmaster Tools is the single most authoritative data source for how Gmail perceives your domain. It shows four reputation levels: HIGH, MEDIUM, LOW, and BAD. A domain at LOW is in serious trouble. A domain at BAD is effectively burned for Gmail — which represents roughly 30-40% of all email recipients.

If you do not have Google Postmaster connected, set it up now. It takes 5 minutes and requires adding a DNS TXT record to verify domain ownership. The tool shows reputation, spam rate, authentication ratios (SPF, DKIM, DMARC), and delivery errors. Note that data has a 24-48 hour delay, so what you see today reflects your sending from 1-2 days ago.

What to do: If reputation is LOW, stop live campaigns and run warmup-only for 2-3 weeks. Monitor Postmaster daily for improvement. If reputation is BAD and has been for more than 2 weeks, recovery is unlikely — begin preparing a replacement domain. See our domain reputation recovery guide for the full process.

4. Listed on critical blacklists

Being listed on Spamhaus SBL/DBL or Barracuda BRBL is one of the strongest signals of a burned domain. These blacklists are checked by virtually every major ISP and corporate mail server. A Spamhaus listing means your emails are being rejected or spam-filtered by the majority of recipients worldwide.

Check using MXToolbox Blacklist Check or Superkabe’s built-in 410-DNSBL monitoring. Being on minor blacklists (UCEPROTECT, PSBL) is concerning but not definitive. Being on Spamhaus or Barracuda alongside other warning signs almost certainly means the domain is burned.

What to do: Follow the blacklist removal process. Fix the root cause first, then request delisting. If the listing has persisted for more than 30 days, domain replacement is usually faster than waiting for reputation recovery after delisting.

5. Open rate dropped to near zero

Cold email open rates typically range from 15-30% for well-targeted campaigns. If your open rate has dropped below 5% and you have verified that your subject lines are not the problem (test the same subject lines from a different, healthy domain), the emails are landing in spam. ISPs are not even showing them to recipients.

A gradual decline over weeks suggests progressive reputation damage. A sudden drop to near-zero suggests an acute event — a blacklisting, a DNS failure, or a recipient server blocking your domain entirely. Check your sending platform’s analytics for the date the decline started and cross-reference with any changes you made (new campaign, volume increase, new lead source).

What to do: Send the same email from a healthy domain to a small test list. If open rates are normal from the other domain, the issue is confirmed as domain reputation. If open rates are low from both domains, the problem may be content-related or ISP-wide.

6. Warmup tool shows declining scores

If you are running warmup alongside live campaigns (which you should be), your warmup tool will show inbox placement scores. A healthy warmup score is 85-100%. If warmup scores are declining — dropping from 90% to 70% to 50% over successive days — your domain reputation is actively degrading and the warmup cannot keep up.

Warmup tools like Warmup Inbox or Instantly’s built-in warmup show how many of their test emails landed in inbox vs spam. This is a leading indicator — warmup scores often decline 3-5 days before live campaign metrics show problems because warmup systems check placement actively rather than relying on open tracking.

What to do: If warmup scores drop below 70%, reduce live volume by 50% immediately. If they drop below 50%, stop live campaigns entirely and run warmup-only until scores recover above 85%. See our guide on why cold emails go to spam after warmup.

7. ISP error codes mention “reputation”

When emails bounce or are rejected, the receiving server returns an error code and message. If you see messages like “550 5.7.1 Our system has detected that this message is likely suspicious due to the very low reputation of the sending domain” (Gmail) or “550 5.7.606 Access denied, banned sending IP” (Outlook), the ISP is explicitly telling you that your reputation is the problem.

Check your bounce logs in Smartlead, Instantly, or whatever platform you use. Filter for 5xx error codes (permanent failures) and look for keywords like “reputation,” “spam,” “blocked,” “denied,” or “policy.” These are different from invalid address bounces (which say “user unknown” or “mailbox not found”) and indicate domain-level reputation problems.

What to do: Document which ISPs are returning reputation-based rejections. If it is only one ISP, targeted recovery is possible. If multiple ISPs are rejecting on reputation, the domain is burned and replacement should be prioritized.

Recovery vs replacement: a decision framework

Not every damaged domain needs to be replaced. Some can be recovered with time and effort. Use this framework to decide:

Factor	Attempt Recovery	Replace the Domain
Warning signs present	1-2 signs	3+ signs
Postmaster reputation	MEDIUM or LOW	BAD for 2+ weeks
Blacklist status	Not on Spamhaus	On Spamhaus 30+ days
Duration of issues	Under 2 weeks	Over 4 weeks
Domain age	6+ months, established	Under 3 months, easily replaced
Recovery timeline	2-4 weeks warmup-only	2-3 weeks for new domain setup + warmup

If you decide to recover, the process is: stop all live campaigns, run warmup-only for 2-4 weeks, monitor Postmaster Tools daily, fix all DNS issues, and gradually reintroduce live volume at 25% of previous levels. Read the full process in our domain burnout recovery guide.

How Superkabe detects domain burnout early

The 7 warning signs above are all detectable before the domain is fully burned — if you have monitoring in place. Superkabe tracks all of these signals in real time and takes automated action to prevent burnout:

Predictive risk scoring: Superkabe assigns a health score to every domain and mailbox based on bounce rate trends, blacklist status, DNS health, and sending patterns. When a domain’s score declines, you get an alert before the damage becomes visible in campaign metrics.

Auto-pause before the 3% threshold: Superkabe does not wait until a domain is burned to act. Mailboxes are auto-paused when bounce rates approach dangerous levels — typically at the 2-2.5% range — before ISPs have time to downgrade your reputation.

5-phase healing pipeline: Paused mailboxes enter Superkabe’s automated recovery pipeline — assessment, cooldown, re-warmup, validation send, and restoration. This is the same recovery process described above, but fully automated.

Continuous DNS and blacklist monitoring: Superkabe checks SPF, DKIM, and DMARC health and queries 410 blacklists continuously. DNS failures and new blacklist listings trigger immediate alerts.

Frequently Asked Questions

How long does it take to burn a cold email domain? ▾

A domain can burn in as little as 3-5 days if bounce rates spike above 5% or spam complaints exceed 0.3%. Under normal conditions with moderate issues, burnout typically happens over 2-4 weeks. Well-managed domains can last 6-12 months. The speed depends on volume, bounce rate, complaint rate, and whether you are monitoring for early warning signs.

Can I use a burned domain for anything else? ▾

A burned sending domain should not be used for cold email, but it can still work for landing pages, website hosting, or warm email to opted-in contacts. The sending reputation is damaged, not the domain itself. Some teams park burned domains for 6-12 months then attempt re-warming, though success rates are low for domains that were on critical blacklists.

How many backup domains should I have for cold email? ▾

Keep 1.5-2x the number of domains you are actively sending from as backups in various warmup stages. If you send from 10 domains, have 5-10 more warming up. Each domain should have 2-3 mailboxes sending no more than 50-75 emails per day. Read our daily sending limits guide for detailed scaling recommendations.