Warmerly
16 blocklist registries checked, 6 for domains and 10 for IPs.
Warmerly
Mailwarm
One-to-one · Blacklist monitoring
Blacklist monitoring
One row, in depth: what each tool does, the verified numbers, and who each suits.
Mailwarm details read from its pricing page, home page, features page, SMTP warmup page and about page on 21 October 2026.
Warmerly
16 blocklist registries checked, 6 for domains and 10 for IPs.
Mailwarm
Detection across major databases, which it does not name; a free checker is linked.
The short answer
Blacklist monitoring, in one look.
Warmerly checks 16 named blocklist registries, 6 for domains and 10 for IPs. Mailwarm lists blacklist detection across major databases, without naming them, and links a free blacklist checker. Last checked 22 October 2026.
Mailwarm
Detection across major databases, which it does not name; a free checker is linked.
The picture
Drawn side by side.
How Warmerly does it
Warmerly, in detail.
Sixteen registries, queried by plain DNS, with an unknown result never shown as green.
01
Domain registries
Six: Spamhaus DBL, SURBL, URIBL, NordSpam DBL, Spam Eating Monkey URI and s5h.
Warmerly product, checked 21 October 2026
02
IP registries
Ten: Spamhaus ZEN, SpamCop, Barracuda, PSBL, Mailspike, NordSpam, Spam Eating Monkey, Lashback UBL, DroneBL and GBUdb Truncate.
Warmerly product, checked 21 October 2026
03
Unknown is never green
If a registry cannot be queried the result is unknown, and it outranks a warning in the overall verdict.
Warmerly product, checked 21 October 2026
04
A free checker
The free blacklist checker tool on warmerly.com looks a domain up without an account.
Warmerly product, checked 21 October 2026
05
Three well-known lists are left out on purpose
The registry file excludes SORBS, recorded as shut down in 2024, UCEPROTECT, which is pay-to-delist, and Invaluement, which is subscription only. A list that cannot give a free, automated answer is not queried, so it cannot produce a false listing.
Warmerly product, checked 21 October 2026
06
A refusal is not a listing
Several lists answer a refused query with an address inside the same range they use for real listings. Each zone classifies its own codes, and anything unrecognised is shown as an error, not a listing, so being rate-limited does not mark a customer as blacklisted.
Warmerly product, checked 21 October 2026
07
Coverage is reported, not just status
Clean on 13 lists and clean on the 3 that answered while 10 refused are different results, and the card says which. A partial answer is amber and shows the count, instead of a green tick over a check that mostly did not run.
Warmerly product, checked 21 October 2026
08
Policy listings are shown apart
Some lists, such as the Spamhaus PBL, cover whole home or office ranges on principle. Those are shown in their own muted section as This IP range isn't meant for sending, are not an abuse report, and are not alerted on.
Warmerly product, checked 21 October 2026
09
Re-checked about every six hours
Blocklists are re-checked about every six hours. The Re-check now button re-reads DNS at once, but may reuse a recent blocklist result. If one is found you get an alert email, unless you turned alert emails off, and the mailbox Health tab names the lists.
Warmerly product, checked 21 October 2026
10
A safe-to-send label on every mailbox
Each mailbox in Accounts carries a pill: Safe to send, Send with care, Don't send with the reason, or Not checked yet. Not checked yet is never a clean result. It means there is no recent blocklist check, so Warmerly cannot say.
Warmerly product, checked 21 October 2026
11
Which IP it checks, and which it does not
Warmerly checks the mail server the mailbox submits through. For Gmail and Microsoft 365 it does not check an IP, because your mail leaves from the provider's shared servers and you cannot delist those. The screen says your mail server's IP, not your sending IP.
Warmerly product, checked 21 October 2026
How Mailwarm does it
Mailwarm, in detail.
Blacklist detection is listed, with the databases unnamed.
01
Detection listed
Its features page lists blacklist detection across major databases.
mailwarm.com/features · read 21 October 2026
02
Free checker
A free Blacklist Checker is linked from its home page.
mailwarm.com · read 21 October 2026
03
Reputation protection
Its pricing page says invalid inboxes in its network are deactivated automatically to cut bounce risk.
mailwarm.com/pricing · read 21 October 2026
04
Eight databases, six of them named
Its blacklist checker page says it queries 8 blacklist databases at once. It names Spamhaus (ZEN, DBL and CBL), Barracuda Central, SpamCop, SURBL, SORBS and the Composite Blocking List, which is six of the eight, and says other major lists are included.
mailwarm.com/blacklist-checker · read 22 October 2026
05
Email, domain or IP in one box
The checker accepts an email address, a domain name or an IP address, detects which one you typed and extracts the part it needs. Results give a status for each list, with names, descriptions and removal guidance if needed.
mailwarm.com/blacklist-checker · read 22 October 2026
06
Five checks a day
The page shows a counter reading 5 checks remaining today, so there is a daily limit. It does not say how the limit resets or whether it is per person.
mailwarm.com/blacklist-checker · read 22 October 2026
07
Monitoring is advised, not described
The page recommends regular checking and says it helps you catch problems early. It does not describe scheduled checks, automatic alerts, notifications or a monitoring dashboard, so we treat ongoing monitoring as a recommendation.
mailwarm.com/blacklist-checker · read 22 October 2026
08
A five-step way off a list
Its steps are confirm the listing, find and fix the cause, check SPF, DKIM and DMARC, request removal from each list, and rebuild reputation slowly at low volume. It links four delisting pages and says requesting removal before the cause is fixed usually leads to relisting.
mailwarm.com/blacklist-checker · read 22 October 2026
09
Causes it lists
Six causes: spam traps from old or purchased lists, spam complaints, compromised accounts or servers, sudden volume spikes, shared IP neighbours and missing authentication. It says most listings are preventable.
mailwarm.com/blacklist-checker · read 22 October 2026
10
Blocklist results inside its deliverability test
Its free deliverability test checks the sending IP and domain against major blocklists and names Spamhaus ZEN, Spamhaus DBL and Barracuda as examples. Lists that cannot be reached show as Couldn't check, never as clean.
mailwarm.com/email-deliverability-test · read 22 October 2026
What Mailwarm does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- Which databases are checked
- How often
- Whether it alerts you
- Which two of the eight databases are unnamed
- Whether the databases checked for paying customers are the same as in the free tool
- Whether a listing triggers an alert email, a notification or a dashboard flag
- How often a connected mailbox is re-checked
- Whether the sending IP is read from the mail's Received header or from the SMTP host
Where the sources disagree
We report each version rather than pick one.
- Its checker page says 8 databases and also says other major blacklists are included, so the number and the wording do not quite match.
The numbers
Only what we could verify.
| Measure | Warmerly | Mailwarm |
|---|---|---|
| Blacklist monitoring | 16 blocklist registries checked, 6 for domains and 10 for IPs. | Detection across major databases, which it does not name; a free checker is linked. |
| Blacklists checked | 16 registries | Not named |
| Domains and IPs | Both | Not stated |
| Free checker | Yes | Yes |
| Registries named | 16 of 16 | 6 of 8 |
| Free checks a day, as shown | Free tool, no account | 5, from a live counter |
| Re-check interval | About every 6 hours | Not described |
| Lists that could not answer | Shown as an error with a count | Couldn't check, in its deliverability test |
| Delisting pages linked | A link per list on the blocklist row | 4: Spamhaus, Barracuda, SpamCop, SURBL |
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
Named against unnamed
You can read which 16 registries Warmerly queries. For Mailwarm we can only say it lists detection across major databases.
Count what you can verify
Warmerly names all 16 registries it asks, so you can see what a clean result covers. Mailwarm names 6 of its 8, so a clean result covers at least those six and two we cannot name. The difference is 10 named lists, 16 against 6.
One list, two histories
Both tools name SpamCop, Barracuda, Spamhaus and SURBL. Warmerly leaves out SORBS, which its docs record as shut down in 2024, and Mailwarm's checker lists it. We cannot say what an answer from a retired list means in Mailwarm's report, so ask before acting on one.
A listing on a Gmail mailbox
If you warm a Gmail or Microsoft 365 mailbox, Warmerly checks the domain lists and does not check an IP, since you cannot delist a provider's shared server. Mailwarm's page says to check the sending IP as well as the domain, because they are separate lists, without saying how that applies to a hosted mailbox.
Alerts decide how fast you learn
Warmerly checks about every six hours and emails you on a listing, so a listing that appears just after one check can wait up to about six hours for the next. Mailwarm's checker is a page you visit, and we found no alert described, so the speed depends on you remembering to look.
Fix the cause before you ask for removal
Both tools agree on the order. Warmerly's help says stop cold sending from the domain, keep warmup running, find the cause, fix it, then request removal. Mailwarm says requesting removal before the cause is fixed usually leads to relisting. A purchased list is the usual cause in both.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You want to see exactly which registries are queried
- You want to read every list that was asked and how many answered
- You want a mailbox-level safe-to-send label and an alert email on a listing
Mailwarm
Mailwarm is the better fit if
- You want blacklist detection bundled with warmup and expert review
- You want removal links for four major lists in one report
- You want a one-off check of an email, domain or IP without an account
Questions
Does Mailwarm monitor blacklists?
Its features page lists blacklist detection across major databases. It does not name them. A free Blacklist Checker is linked.
Which lists does Warmerly check?
Six for domains and ten for IPs, 16 in all, including Spamhaus.
How many blacklists does Mailwarm check?
Its checker page says 8, and names six of them: Spamhaus, Barracuda Central, SpamCop, SURBL, SORBS and the Composite Blocking List (mailwarm.com/blacklist-checker, read 22 October 2026).
What does a partial answer mean on Warmerly?
Some lists refuse automated lookups at times. The card then says clean on the lists that answered and shows how many did not. It is not a listing, and the check is retried.
Sources
- Mailwarm features
- Mailwarm home page
- Mailwarm pricing
- Mailwarm blacklist checker
- Mailwarm email deliverability test
Mailwarm pages were read on 21 October 2026. Plans and wording change, so check the vendor's own page before you decide. Warmerly details come from the product as it runs today.
More features
See it on your own mailbox.
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