mailX by mailwarm
Free email deliverability and DNS lookup toolkit that checks SPF, DKIM, DMARC, BIMI, MX and blacklists against live DNS.
For a one-shot "why is my mail landing in spam" diagnosis, mailX beats assembling four separate checkers, and the combined SPF + DKIM + DMARC + MX + blacklist audit returns a single plain-English report. The MCP server and JSON API are why it stays in rotation if you're wiring deliverability checks into an AI agent or build pipeline. It's a snapshot, not a monitoring service — don't expect continuous reputation tracking or domain warmup.
Verified 2d ago · liveness 72/100 · cite: rightaichoice.com/tools/mailx-by-mailwarm
- Founders launching cold email, newsletters or transactional flows who need to know why mail is landing in spam
- Sales teams protecting outbound inbox placement before and after a campaign
- Agencies running fast DNS and authentication audits across many client domains
- Developers debugging SPF, DKIM, DMARC, MX, SMTP and IMAP configuration
- Teams that need continuous monitoring and alerting when records drift — mailX returns a snapshot
- Anyone wanting automated domain warmup or sender reputation building
- Users looking for a built-in email sending or campaign platform
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Skip mailX if you need continuous monitoring, alerting when SPF or DKIM records drift, or automated domain warmup — it returns a point-in-time snapshot and hands reputation building to its sibling product Mailwarm.
The site presents mailX as free with no signup, and the published second tier is a Custom-priced API plan for programmatic access. That combination undercuts paid checker subscriptions for teams that only need periodic diagnostics, but it will not replace a monitoring or warmup subscription — buyers who need continuous reputation tracking should budget for that separately. Confirm API rate limits and commercial terms directly before building on the JSON API.
In short
mailX by mailwarm — Free email deliverability and DNS lookup toolkit that checks SPF, DKIM, DMARC, BIMI, MX and blacklists against live DNS. Best for Founders launching cold email, newsletters or transactional flows who need to know why mail is landing in spam, Sales teams protecting outbound inbox placement before and after a campaign, Agencies running fast DNS and authentication audits across many client domains. Free to use.
What's new in mailX by mailwarm
Checked todayAcross the latest 5 updates: 5 news mentions.
DNS Lookup Python: Diagnose Email Deliverability 2026
Guide on using Python DNS lookups to diagnose email deliverability issues, aimed at developers automating checks.
How to Get Mx Record Nslookup: A 2026 Guide
Tutorial covering how to retrieve MX records with nslookup across platforms to troubleshoot email delivery.
The Best Email Spam Checker Tool to Fix Your Deliverability in 2026
Covers a spam checker approach that diagnoses deliverability problems and gives steps to improve inbox placement.
Email with Graphics: A Guide to Stay Out of Spam in 2026
Best practices for using graphics in emails without damaging deliverability or triggering spam filters.
SPF, DKIM and DMARC: The Complete Guide to Email Authentication (2026)
Comprehensive guide to configuring SPF, DKIM and DMARC records for better inbox placement.
What people actually say about mailX by mailwarm — is it worth it?
We ran a structured research pass across product reviews, community discussions, and post-purchase forum threads to surface the patterns vendors won't publish themselves. Below: the recurring strengths, the hidden costs people mention most, and the cohort that consistently regrets adopting this tool.
15 mentions across 1 source (Product Hunt) · researched Aug 29, 2026.
Average across the 1 source that answered — each source counts once, not each post.
- +Free with no signup, lowering barrier to serious diagnostics
- +Plain-English explanations turn DNS jargon into actionable steps
- +Over 20 tools cover DNS, SPF, DKIM, DMARC, blacklist and more
- +MCP integration lets AI agents query deliverability programmatically
- +REST API enables automated diagnostics in custom workflows
- −No account means no audit history or trend tracking
- −Doesn't auto-apply fixes, only suggests them
- −No per-client analysis like Gmail-specific quirks
- −Reputation issues beyond SPF/DKIM/DMARC not fully addressed
- −Launch buzz lacks long-term reliability evidence
- • No explicit hidden costs, but API rate limits may push users to paid tiers if they hit quotas
Viability Score
How well maintained and how widely used is mailX by mailwarm? Built from what the vendor actually publishes (docs, changelog, tutorials, integrations, pricing), whether the site is live, and how much real users discuss it. How we calculate this
Last calculated: October 2026
How we score →Key Features
- Live DNS lookup for A, MX, TXT, CNAME and PTR records
- SPF checker with sender policy validation
- DKIM checker for signature and public key verification
- DMARC checker with policy alignment analysis
- BIMI checker for brand indicator records
- Blacklist / RBL / DNSBL checker for domains and IPs
- SMTP test for mail server connectivity and response time
- IMAP checker for mailbox connectivity
- SMTP Finder and IMAP Finder for server host discovery
- DNS propagation checker across global resolvers
- SPF, DKIM, DMARC, DNS record and email address generators
- Combined audit running SPF + DKIM + DMARC + MX + blacklist in one report
- JSON REST API for automated deliverability diagnostics
- MCP server so AI agents can query live DNS data
- Plain-English explanations and fixes alongside raw results
About mailX by mailwarm
mailX by mailwarm is a free, browser-based diagnostic toolkit for email deliverability and DNS. Enter a domain or IP and it queries live DNS in real time, returning a report covering A, MX, TXT, CNAME and PTR records, SPF, DKIM, DMARC and BIMI authentication, DNS propagation, blacklist (RBL/DNSBL) status, and SMTP/IMAP connectivity. There's nothing to install, and the vendor states no signup is required. The toolkit runs to 20+ individual tools. Checkers for SPF, DKIM, DMARC, BIMI and blacklists sit alongside generators for SPF, DKIM, DMARC, DNS records and email addresses, plus MX Lookup, SMTP Test and SMTP Finder, IMAP Checker and IMAP Finder, PTR/reverse DNS, and a DNS propagation checker. You can select several tools and run them together on one domain, and the combined audit returns SPF + DKIM + DMARC + MX + blacklist in a single report with plain-English explanations rather than raw record dumps. Two things separate it from MXToolbox-style checkers. The one-click combined audit condenses what usually takes several tabs into one pass, and every tool exposes an MCP server plus a JSON API — the published install line is `claude mcp add --transport http mailx https://themailx.com/mcp` — so an AI agent or internal script can pull live DNS data programmatically. The site claims 50,000+ marketers and developers. Who it's for: founders running cold email, newsletters or transactional flows who need to know why mail is landing in spam; sales teams protecting outbound inbox placement; marketing teams chasing campaign performance; agencies auditing many client domains; and developers debugging mail infrastructure. Treat mailX as a diagnostic layer — it tells you what's broken. It does not warm your domain, monitor reputation over time, or send mail for you; the vendor points to Mailwarm for reputation building.
Behind the Verdict
We'd reach for mailX the moment an outbound campaign starts underperforming and nobody can say why. Point it at the domain, run the combined audit, and you get SPF, DKIM, DMARC, MX and blacklist results in one report instead of five tabs. The plain-English fixes matter here: the report is written for people who don't read TXT records for fun, which is most of the people who actually need this. The MCP server is the part that surprised us. Instead of copying DNS values into a ticket, you can hand an AI agent the endpoint and let it pull live records on demand. For teams building internal ops tooling, that turns mailX from a website into a data source. The JSON API does the same for scripts and CI checks. Where it bites: mailX returns a snapshot. If someone edits a DNS record next Tuesday and silently breaks DKIM alignment, you'll only know when you run the check again. There's no alerting, no drift monitoring, no reputation graph over time. Pair it with a monitoring product if that matters. It also won't warm a domain, send mail, or replace your ESP. The vendor is explicit that Mailwarm handles reputation building. If your problem is "we've never sent from this domain before," mailX tells you whether your records are right — not how to build sending history. Against MXToolbox, the case is speed and modern plumbing. MXToolbox is deeper on some legacy diagnostics; mailX is faster to the one-click combined report and wins outright for anyone who wants an MCP endpoint or a clean JSON response. For a free tool with no signup, the tradeoff is easy to take. The generators are the underrated half. If you're setting up a new domain, you can generate the SPF, DKIM, DMARC and DNS records, publish them, then immediately re-run the checkers in the same place. That loop —
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Real-world workflow fit
Concrete scenarios for the personas mailX by mailwarm actually fits — and what changes day-one when you adopt it.
Emails started landing in spam ahead of a launch. You enter the sending domain, tick the combined audit and get SPF, DKIM, DMARC, MX and blacklist results in one report.
Outcome: A specific record edit to fix, plus confirmation that the domain is not listed on any RBL/DNSBL — re-run the audit after the DNS change to verify.
You onboard a new client and need a baseline before touching their setup. You run the combined audit plus MX, TXT and PTR lookups on the client domain, then the SPF, DKIM and DMARC generators to draft corrected records for their DNS provider.
Outcome: A repeatable per-client audit that takes minutes instead of an afternoon of tab-juggling, with fixes you can paste straight into the client's DNS panel.
You add the MCP endpoint to Claude with `claude mcp add --transport http mailx https://themailx.com/mcp`, or call the JSON REST API from a script, so a pre-send check pulls live DNS and authentication state automatically.
Outcome: Deliverability state becomes a programmatic input rather than a manual browser check, though you should confirm API rate limits and terms before depending on it at volume.
Use Cases
- Run one combined audit against your sending domain to confirm SPF, DKIM, DMARC, MX and blacklist status before a campaign
- Check whether your domain or sending IP appears on RBL/DNSBL spam databases after a deliverability drop
- Test SMTP and IMAP server connectivity and response times when mail is not being accepted or retrieved
- Add the MCP endpoint to an AI assistant so it can pull live DNS and authentication data mid-task
- Generate correct SPF, DKIM, DMARC or DNS records for a new domain before pasting them into your DNS provider
- Diagnose why a client's emails land in spam during an agency audit across multiple domains
- Verify DNS propagation after changing records, using the propagation checker across resolvers
- Debug MX, TXT, CNAME and PTR records when email routing or domain configuration breaks
Limitations
- mailX is a diagnostic toolkit, not a sending or reputation-management platform.
- It runs live DNS and mail-server checks against your domain or IP but does not warm up domains, monitor reputation over time, or send email — the vendor points to Mailwarm for reputation building.
- Results reflect DNS state at the moment of the check, so fixes must be re-verified by re-running the tool; there is no historical trend or alerting.
- Blacklist and infrastructure findings are informational, and the site's own guidance is that blacklist listings and poor engagement both feed sender reputation, which mailX does not manage.
- The material available does not document API rate limits or usage caps, so high-volume automated users should confirm limits directly.
as of 2026-10-09
Verification history
We have re-verified mailX by mailwarm 9 times since . Each pass re-reads the vendor's own pages and re-checks every listed field against that evidence; passes where nothing had changed are marked as such.
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-checked, vendor evidence unchanged
- — re-verified summary, description, our verdict, our analysis, pricing model, pricing tiers, features, integrations, who it suits, who should skip it
- — re-checked, vendor evidence unchanged
- — re-checked, vendor evidence unchanged
Showing the 6 most recent of 9 verification passes.
Free to cite with attribution — this page re-verifies continuously.
12-month cost
Project the real annual outlay, including the implied monthly cost when only an annual tier is published.
Vendor list price only. Add-on usage, seat overages, and contract minimums are surfaced under Hidden costs & gotchas.
Plans compared
For each published mailX by mailwarm tier: who it actually fits, and what it adds vs. the previous tier. Cross-reference the cost calculator above for projected annual outlay.
Free
$0/mo
Ideal for
Founders, sales and marketing teams, agencies and developers who need periodic SPF, DKIM, DMARC, MX and blacklist diagnostics without installing anything.
What this tier adds
Starting tier — 20+ DNS lookup and deliverability tools, combined audit in one report, plain-English fixes, no signup per the site.
API
Custom
Ideal for
Developers and teams wiring live DNS and authentication checks into an AI agent, internal tool or build pipeline.
What this tier adds
Adds JSON REST API and MCP server access to live DNS and deliverability data; priced as Custom.
Where the pricing makes sense
The company stage and team size where mailX by mailwarm's pricing actually pencils out — and where peers do it cheaper.
The site presents mailX as free with no signup, and the published second tier is a Custom-priced API plan for programmatic access. That combination undercuts paid checker subscriptions for teams that only need periodic diagnostics, but it will not replace a monitoring or warmup subscription — buyers who need continuous reputation tracking should budget for that separately. Confirm API rate limits and commercial terms directly before building on the JSON API.
Setup time & first value
How long it actually takes to get something useful out of mailX by mailwarm — broken out by persona, not the marketing-page minute.
Fastest path is the combined audit: enter your domain or IP and you have live SPF, DKIM, DMARC, MX and blacklist results in seconds, with no install and no signup per the site. Developers wiring in the MCP server or JSON API need a few minutes to add the endpoint and confirm responses before it becomes part of a pipeline.
Switching to or from mailX by mailwarm
How to bring data in from common predecessors and how to get it back out — written for the switcher, not the buyer.
- →From MXToolbox: paste your domain into the combined audit instead of running separate SPF, DKIM, DMARC, MX and blacklist lookups across tabs
- →From manual dig/nslookup checks: use the DNS lookup, MX lookup, TXT lookup, CNAME lookup and PTR lookup tools for the same records with plain-English explanations
- →From scattered single-purpose free checkers: consolidate on the 20+ tool set and run multiple selected tools in one pass per domain
- →From ad-hoc agent scripting: replace custom DNS parsing with the published MCP endpoint or the JSON REST API
- ↗To Mailwarm: if you need domain warmup and sender reputation building rather than one-shot diagnosis, the vendor positions Mailwarm as that product
- ↗To a monitoring or deliverability platform: if you need trend history and alerts when SPF, DKIM or DMARC records drift, a snapshot checker cannot cover it
- ↗To a sending platform: if you need campaign sending, scheduling and inbox placement control rather than diagnostics
Integrations
Resources & Guides
Tutorials & Learning
Why Emails Go to Spam (And How to Fix It in Seconds) - mailX by mailwarm
mailX by mailwarm (YC S20)
What if we turn all your emails to a lead magnet ? #email #deliverability #growthhacking
mailX by mailwarm (YC S20)
YouTube returned 6 videos for “mailX by mailwarm”, and we withheld 4: 4 did not mention mailX by mailwarm. Showing the 2 we can prove are about mailX by mailwarm.
Official links
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Featured Head-to-Head Comparisons
Mailx By Mailwarm vs Spider Cloud
These are complementary tools for entirely different jobs. Choose Spider Cloud if you need a fast, cost-effective web crawling API that feeds structured data into AI agents, RAG pipelines, or LLMs. Choose mailX by mailwarm if you are an email sender, marketer, or developer debugging deliverability issues (SPF, DKIM, DMARC, blacklists) and need a free, no-signup toolkit. Don't compare them head-to-head; pick based on your domain need.
Mailx By Mailwarm vs Chili Piper
Chili Piper and mailX by mailwarm solve entirely different problems. Chili Piper is a premium B2B conversion platform for enterprise teams that want to turn web traffic into meetings in seconds; mailX is a free, no‑signup toolkit for diagnosing email deliverability issues. Choose Chili Piper if you have high inbound volume and need automated booking and routing. Choose mailX if your emails are landing in spam and you need quick DNS checks.
Mailx By Mailwarm vs Temporal Ai
Temporal AI and mailX by mailwarm serve completely different needs. Temporal is a robust orchestration platform for teams building fault-tolerant AI agents and multi-step workflows. mailX is a free toolkit for diagnosing email deliverability. Choose Temporal when you need reliable execution and state recovery; choose mailX for quick DNS and email authentication checks. They aren't competitors.
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