WarmerlyWarmerly ahead on this row
Checked every six hours per mailbox, with a written fix for each finding; free DMARC reports.
Warmerly
Warmbox
One-to-one · SPF, DKIM and DMARC checks
SPF, DKIM and DMARC checks
One row, in depth: what each tool does, the verified numbers, and who each suits.
Warmbox details read from its pricing, home, features, agency and checker pages and its help centre on 21 October 2026.
Warmerly
Checked every six hours per mailbox, with a written fix for each finding; free DMARC reports.
Warmbox
A live checker on every plan and a free checker with 100+ blacklists; described as a one-off check-up.
The short answer
SPF, DKIM and DMARC checks, in one look.
Warmerly checks SPF, DKIM and DMARC for every mailbox every six hours and writes a fix for each finding. Warmbox lists a Live Email Checker (DNS and blacklist) on every plan, and a free checker that audits 100+ blacklists and inspects SPF, DKIM and DMARC. Its page describes a one-off check-up; whether it re-runs on its own is not stated. Last checked 22 October 2026.
Warmbox
A live checker on every plan and a free checker with 100+ blacklists; described as a one-off check-up.
The picture
Drawn side by side.
How the records get checked
SPF, DKIM, DMARC and MX
WarmerlyWarmbox
WarmerlyEvery 6 hours, on its own
- SPFChecked, with a written fix
- DKIMChecked, with a written fix
- DMARCChecked, with a written fix
- MXChecked
WarmboxRun the checkA check-up when you run it
- SPF, DKIM, DMARCInspected
- BlacklistsMore than 100 checked
- AuditMore than 120 checkpoints, with a score
- MXNot mentioned
Warmbox also lists a Live Email Checker on every plan. Its page does not say whether the checks re-run on their own.
How often, over a day
From midnight to midnight
WarmerlyWarmbox
WarmerlyA records sweep every 6 hours
MidnightMidnight
WarmboxNot stated: described as a check-up, with reports kept in your dashboard
Warmerly's six hours come from its scheduler. We found no schedule for Warmbox's checks.
On screen
What it looks like.
WarmerlySample data
How Warmerly does it
Warmerly, in detail.
Every mailbox checked every six hours, with a written fix.
01
Checked every six hours
The records sweep runs every six hours across every mailbox that is not dead or paused. A Re-check now option is on the mailbox Health tab.
Warmerly product, checked 21 October 2026
02
A written fix for each finding
Each finding has a title, an explanation and a fix. SPF is checked for the 10-lookup limit, DKIM for key length and test mode, DMARC for policy and reporting address.
Warmerly product, checked 21 October 2026
03
Unknown is never green
A check that could not run is shown as unknown, not as fine.
Warmerly product, checked 21 October 2026
04
Free DMARC report collection
Point your DMARC reporting address at a Warmerly address to see who sends as your domain and whether they pass, for up to 10 domains per workspace.
Warmerly product, checked 21 October 2026
05
Quality, not just presence
SPF is checked for its ending rule, the 10-lookup limit counted through includes and redirects, and malformed address terms. DKIM is checked for key length (1024 bits or fewer is flagged as weak) and test mode. DMARC is checked for policy, subdomain policy, percentage and a reporting address.
Warmerly product, checked 21 October 2026
06
Three severities
Each finding is a fail, a warn or an info note. Only fails can colour a domain red, and one hard failure is amber and two or more is red, so a working domain with a monitor-only DMARC policy is not painted as broken.
Warmerly product, checked 21 October 2026
07
Advisories never email you
The sweep alerts only on a hard failure, not on every domain that is less than perfect. Most healthy domains publish a monitor-only DMARC policy, and alerting on that would have mailed owners about something that is not broken.
Warmerly product, checked 21 October 2026
08
Sixteen named blocklist zones
Six domain zones (Spamhaus DBL, SURBL, URIBL, NordSpam, Spam Eating Monkey and s5h) and ten IP zones (Spamhaus ZEN, SpamCop, Barracuda, PSBL, Mailspike, NordSpam, Spam Eating Monkey, Lashback, DroneBL and GBUdb) are queried by plain DNS lookup.
Warmerly product, checked 21 October 2026
09
A refusal is not a listing
If a list refuses our query, for example because of rate limits, the card shows an error and not a listing. A partial answer is shown amber with the count of lists that answered.
Warmerly product, checked 21 October 2026
10
The record to publish
Under a failing SPF or DMARC check the card shows the exact record to add, merged into the SPF record that is live now, and never a second SPF record, with a copy button.
Warmerly product, checked 21 October 2026
11
Shared consumer domains are handled honestly
On gmail.com or outlook.com the records belong to the provider, so Warmerly marks non-passing records unknown instead of telling you to fix something you cannot change.
Warmerly product, checked 21 October 2026
12
Re-checks are rate limited
A Re-check now request is held to one per six hours per domain, the same as the sweep interval, so pressing it repeatedly cannot multiply lookups across the blocklist operators.
Warmerly product, checked 21 October 2026
How Warmbox does it
Warmbox, in detail.
A live checker on every plan and a free public checker with a wide blacklist sweep.
01
Live Email Checker
"Live Email Checker (DNS, Blacklist)" is listed among the features included in all plans.
warmbox.ai/pricing · read 21 October 2026
02
Free checker
The checker page says it is "totally free" and shows no limits. It verifies more than 100 IP and domain blacklists and inspects SPF, DKIM and DMARC.
warmbox.ai/ips-domains-blacklist-dns-settings-deliverability-checker · read 21 October 2026
03
120 checkpoints
The features page says the audit is based on more than 120 checkpoints and returns a score.
warmbox.ai/the-best-email-warm-up-solution-discover-our-features · read 21 October 2026
04
Reports
The help centre has articles on running a deliverability check, sending a test email, getting a report and sharing a report.
help.warmbox.ai/en · read 21 October 2026
05
Eleven domain and IP checks in one report
The help centre says a deliverability report lists domain blacklist, IP blacklist, SpamAssassin score, SPF, DKIM, DMARC, reverse DNS, domain age, List-Unsubscribe header, broken links and short URLs, each linked to a guide.
help.warmbox.ai/en/articles/5239460-get-my-email-deliverability-report · read 22 October 2026
06
A score out of 100
The report aggregates more than 120 items into one Deliverability Score. A score below 30 is considered spam and a score above 80 is considered good.
help.warmbox.ai/en/articles/5239460-get-my-email-deliverability-report · read 22 October 2026
07
Check by sending a test email
To run a check you send an email to a Warmbox address shown in the dashboard. The analysis can take up to 2 minutes.
help.warmbox.ai/en/articles/5239459-send-a-test-email · read 22 October 2026
08
A public link to share
A report can be shared through a public link from the Email Spam Checker dashboard, with a Share my report button.
help.warmbox.ai/en/articles/5239462-share-my-email-deliverability-report · read 22 October 2026
09
A 25-guide deliverability library
The help centre has an Email Deliverability Guide of 25 articles covering domain and IP blacklisting and delisting, SpamAssassin, SPF, DKIM, DMARC, reverse DNS, domain age, List-Unsubscribe, broken links and short URLs.
help.warmbox.ai/en/collections/2951595-the-email-deliverability-guide · read 22 October 2026
10
Delisting advice
The guide says most blacklists drop a domain after a while, usually 1 to 3 weeks, and that some offer self-service removal forms where you should explain your activity.
help.warmbox.ai/en/articles/5239476-how-to-get-delisted-from-domain-blacklist · read 22 October 2026
11
Domain age explained
The guide says a domain created less than 3 months ago is more likely to have deliverability issues, and that age is one factor among others.
help.warmbox.ai/en/articles/5239526-what-is-domain-age-and-how-does-it-impact-my-email-deliverability · read 22 October 2026
12
SpamAssassin explained
The guide describes SpamAssassin as scoring each email with 5 considered spam, and says a score of 4 or above hurts deliverability.
help.warmbox.ai/en/articles/5239482-what-is-spamassassin-and-how-your-score-is-calculated · read 22 October 2026
What Warmbox does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- Whether the checks re-run on a schedule
- MX record checks, which the checker page does not mention
- Whether an account is needed to run the free checker
- How the Deliverability Score weights each item
- Whether any record is monitored after the first test
- Whether an alert is sent when a record breaks
Where the sources disagree
We report each version rather than pick one.
- The checker page says more than 100 blacklists are verified and the features page says the audit is based on more than 120 checkpoints. These may be different counts (blacklists against all items), but neither page explains the difference.
- The pricing page lists a Live Email Checker (DNS, Blacklist) in all plans, but the help centre describes a test you start by emailing a Warmbox address. Whether the live checker re-runs by itself is not stated.
The numbers
Only what we could verify.
| Measure | Warmerly | Warmbox |
|---|---|---|
| SPF, DKIM and DMARC checks | Checked every six hours per mailbox, with a written fix for each finding; free DMARC reports. | A live checker on every plan and a free checker with 100+ blacklists; described as a one-off check-up. |
| How often records are checked | Every 6 hours | Not stated |
| Blacklists checked | Free blacklist checker on its site | More than 100 |
| Checkpoints in an audit | Not published | More than 120 |
| Free DMARC reports | Up to 10 domains | Not stated |
| Domain blocklists named | Six zones | Not named, 100+ blacklists across IP and domain |
| IP blocklists named | Ten zones | Not named, 100+ blacklists across IP and domain |
| Items in a report | Not published | More than 120, one score out of 100 |
| Score meaning | No single score for DNS | Below 30 spam, above 80 good |
| Time for a check | Sweep every 6 hours, Re-check now once per 6 hours per domain | Up to 2 minutes after the test email |
| Guides on SPF, DKIM, DMARC and blacklists | Findings with a written fix | 25 guides in the help centre |
| Shareable report link | Not stated | Yes, public link |
| Weak DKIM key flagged | 1024 bits or fewer | Not stated |
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
A check once is not monitoring
A one-off audit shows today. A record that breaks next week only shows up if something re-checks it.
Use both free checkers
Both companies offer a free public checker. Run them on the same domain and compare what they say.
Warmerly watches, Warmbox reports
Warmerly's sweep runs by itself every six hours. Warmbox's help pages describe a test you start by sending an email, so a record that breaks later is only seen when you run another test.
A score and a list answer different questions
Warmbox gives one score out of 100 and a long library to read. Warmerly gives a status for each record with a written fix. Some people want the score, some want the fix.
Check the same domain in both
Run Warmbox's free checker and Warmerly's Health tab on one domain and compare. Where they disagree, trust the record you can read yourself in DNS.
Shared domains are different
On a mailbox at gmail.com or outlook.com the records belong to the provider. Warmerly says so rather than asking you to fix them; Warmbox does not say how it treats these.
Fixing is still your job
Neither tool edits your DNS. Each tells you what to publish, so allow time for your domain host to apply a change.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You want records re-checked on their own, with a written fix
- You want free DMARC report collection
- You want records re-checked every six hours without starting a test
- You want the exact record to publish, merged into your live SPF
- You want a failing check to say unknown rather than pass
- You want to read free DMARC reports for up to 10 domains
- You want blocklist refusals reported as errors, not listings
- You want a clear split between failures and advice
Warmbox
Warmbox is the better fit if
- You want a free public checker with a stated 100+ blacklist sweep
- You want a shareable deliverability report
- You want one Deliverability Score out of 100
- You want a 25-guide library on SPF, DKIM, DMARC and blacklists
- You want a public link to share a report with a client
- You want a free checker you can run before you sign up
- You want reverse DNS, domain age and link checks in the same report
- You want SpamAssassin explained alongside your results
Questions
How often does Warmerly check DNS records?
Every 6 hours, and you can re-check a domain once per 6 hours on demand. Warmbox does not state a schedule.
How many blacklists does Warmbox check?
More than 100, across IP and domain lists. Warmerly names six domain zones and ten IP zones.
What does a Warmbox report score mean?
One score out of 100 from more than 120 items: below 30 is spam and above 80 is good.
Does Warmerly offer DMARC reports?
Yes, free for up to 10 domains. Warmbox does not state this.
Does Warmerly flag weak DKIM keys?
Yes, keys of 1024 bits or fewer.
Sources
- Warmbox deliverability checker
- Warmbox pricing
- Warmbox features
- Warmbox help: get my deliverability report
- Warmbox help: send a test email
- Warmbox deliverability guide
Warmbox 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.
Connect a mailbox. Warmerly runs alongside whatever you send from now, so you can compare before you move anything.
Free plan, no card. Paid plans: 7-day trial, first charge on day 8.