An email blacklist check tells you if your domain or IP is blocklisted. Check both the sending and link domains, and prioritize the Tier 1 lists.
An email blacklist check looks up your sending domain, your tracking or link domain, and your sending IP against known blocklists to see if any of them are flagged for spam. If you are on a Tier 1 list like Spamhaus, your inbox placement can drop to near zero, so this is the first thing to check when deliverability falls off a cliff. The check takes two minutes with a free multi-list tool. The mistake most people make is checking only the sending domain and missing that the shortened link domain in their emails is the one that got listed. This post covers how to run the check; for the fix, see how to get off an email blacklist.
An email blacklist check is a lookup that tests whether a sending domain, a link or tracking domain, or an IP address appears on one or more DNS-based blocklists used by mail providers to filter spam. Listings on major blocklists such as Spamhaus can cause severe or total loss of inbox placement, so regular checks of every domain and IP involved in sending are standard deliverability hygiene.
A blacklist, or blocklist, is a published list of domains and IP addresses associated with spam. Mail providers query these lists in real time when deciding whether to accept, folder, or reject a message. A listing on a widely used blocklist is a direct signal to filter your mail.
The lists are not equal. Spamhaus is generally treated as the only Tier 1 blocklist, meaning the major providers weight it heavily, and a Spamhaus listing can cause near-total inbox loss for the affected domain or IP. Other lists like SpamCop, Barracuda, and SORBS matter less individually but add up. Some are noisy and rarely consulted. See cold email deliverability guide and why are my emails going to spam.
You end up on a blocklist by tripping a spam trap, generating complaints, sending to a honeypot address, or having a compromised account send spam. High bounce rates and scraped lists are the most common root causes for cold senders. See how to clean a B2B email list.
You need to check three things, not one:
Missing the link domain is the classic error. If your emails use a shortened tracking domain and that domain gets listed, your mail is filtered even though your From domain is clean.
Because Spamhaus is Tier 1, check it directly at check.spamhaus.org, which looks across Spamhaus blocklists in one place. For a domain-specific check, Spamhaus also has a DBL (domain blocklist) lookup. A clean Spamhaus result is the single most important line in the whole check. See MailGenius's Spamhaus guide.
Then run each domain and the IP through a multi-list tool. MXToolbox checks 80-plus lists, MultiRBL.valli.org is the most exhaustive, and several free blacklist checkers test the 9 or so major lists in seconds. What good looks like: clean or "not listed" on every list that matters, and only noisy or obscure lists showing hits, if any. See Cleanlist's blacklist checker.
A hit on Spamhaus, SpamCop, or Barracuda is serious and needs action. A hit on an obscure list that no major provider consults is usually noise; note it and move on. If you are listed on a Tier 1 list, stop sending from that domain or IP until it is resolved, because continued sending while listed deepens the reputation damage.
Run the check monthly, and immediately any time you see a sudden delivery drop, a spike in bounces, or a complaint-rate jump. Catching a listing in the first days makes delisting faster. See how to maintain list hygiene in B2B outreach.
Speed matters, because every hour of sending while listed deepens the damage. Work this sequence.
Set up continuous monitoring on your sending and link domains so you learn about a listing within hours, not on your next manual check. See how to maintain list hygiene in B2B outreach.
The Two-Domain Check: always check both your sending domain and your link or tracking domain, plus the sending IP, and prioritize the Tier 1 lists. A clean From domain means nothing if the link domain is listed.
The Two-Domain Check exists because cold email setups usually involve more than one domain, and filters evaluate all of them. Your From address might be you@sending-domain.com, but the links in the email might route through trk.short-domain.co. Both are visible to the filter, and either being blocklisted taints the message. Teams that only check the From domain can chase a deliverability problem for weeks while the real listing sits on a tracking domain they forgot they were using.
Priority matters too. A multi-list checker will happily show a dozen results, most of them irrelevant. The one that decides your fate is Spamhaus, and after that SpamCop and Barracuda. If those three are clean, a hit on some regional list from 2009 is not your problem. Read the results by weight, the same discipline as the spam fault tree.
The quotable version: "Check every domain your email touches, not just the one in the From line. Filters see all of them."
The fastest way to never need this check is to not get listed, and that comes down to list quality: verified addresses, low bounce rates, no spam traps. See what percentage of B2B emails are invalid.
A public blacklist listing and poor Gmail or Outlook placement are related but not the same, and the check for each is different.
A blacklist is a third-party published list that many mail systems consult. You check it with the tools above, and a listing there can affect delivery across many providers at once. Removal is a defined process: fix the cause, request delisting or wait for expiry.
Provider-side filtering is Gmail's, Yahoo's, or Microsoft's own internal reputation judgment about your domain. It is not a public list, there is no lookup tool and no removal form, and it can be poor even when every public blacklist shows you clean. You assess it through Google Postmaster Tools and Yahoo Sender Hub, and you improve it only through sustained clean sending.
So a full deliverability check has two parts: run the blacklist tools for the public lists, and check Postmaster Tools and Sender Hub for the provider-internal picture. A domain can pass one and fail the other. If blacklists are clean but placement is bad, the problem is provider reputation, and the spam fault tree is the way to diagnose it.
Blocklist listings for cold senders almost always trace back to a bad list: spam traps, honeypots, and heavy bounces from scraped data. Sending to verified contacts is the prevention.
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Run an email blacklist check on your sending domain, your link or tracking domain, and your sending IP. Check Spamhaus directly first, then a multi-list tool, and read the results by weight: Spamhaus, SpamCop, and Barracuda are the ones that matter. Do the check monthly and the moment delivery drops. If you are on a Tier 1 list, pause sending from that domain and start delisting. Best of all, keep the list verified so you never trip a trap.
How do I check if my domain is on an email blacklist?
Check Spamhaus directly at check.spamhaus.org first, since it is the Tier 1 list. Then run your sending domain, your link or tracking domain, and your sending IP through a multi-list tool like MXToolbox or a free blacklist checker. Look for clean results on Spamhaus, SpamCop, and Barracuda.
Which blacklists actually matter?
Spamhaus is the one that matters most, treated as Tier 1 by major providers, and a listing there can cause near-total inbox loss. SpamCop and Barracuda are next. Many other lists exist but are noisy or rarely consulted; a hit on an obscure list is usually not your deliverability problem.
Do I need to check my tracking domain too?
Yes, and it is the step people skip. If your emails use a separate short domain for link tracking and that domain gets blocklisted, your mail is filtered even though your From domain is clean. Check every domain that appears anywhere in the message.
Why did my domain get blacklisted?
Common causes for cold senders: sending to spam-trap or honeypot addresses in a scraped list, generating spam complaints from irrelevant targeting, a high bounce rate, or a compromised account sending spam. Bad list quality is the root cause in most cases.
How often should I run a blacklist check?
Monthly as routine, and immediately whenever you see a sudden drop in delivery, a spike in bounces, or a jump in complaint rate. Catching a listing early makes the delisting process faster and limits the reputation damage from sending while listed.
Should I keep sending while my domain is blacklisted?
No. Continued sending from a listed domain or IP deepens the reputation damage and can slow delisting. Pause outbound from that domain, resolve the root cause, submit the delisting request, and warm the domain back up gradually once you are clear.
LSI keywords: email blacklist check, blocklist, Spamhaus, SpamCop, Barracuda, sending domain, link domain, tracking domain, sending IP, MXToolbox, spam trap, delisting
Yahoo sender requirements mirror Gmail's, with one sharper edge: Yahoo rejects non-compliant bulk mail outright instead of foldering it.
Google bulk sender requirements apply at 5,000 emails a day, but the thresholds that filter you apply to everyone. The full 2026 checklist.
How to get off an email blacklist: fix the root cause first, then request delisting. Skip the fix and you get relisted, often faster.
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