Back to Growth Toolbox
Deliverability

MxToolbox

The technical reference for diagnosing email deliverability and DNS configuration problems. SPF, DKIM, DMARC and blacklist verification. First reflex when emails stop arriving.

Try the tool
Who's it for?OpsGrowth

Review by a Growth Engineer

My verdict: the technical Swiss army knife of deliverability.

MxToolbox is the essential tool for diagnosing DNS and deliverability problems. Technical but powerful. The technical reference for diagnosing email deliverability problems.

MxToolbox lets you check your DNS configurations (SPF, DKIM, DMARC), test if your domain is blacklisted, analyze your MX records, etc. It's the tool for sys admins and technical growth engineers. The free plan is already powerful, Pro at $139/year adds monitoring. If you do cold email seriously, you'll use it regularly. Austere but ultra-effective interface.

What I like less: the technical and austere interface that can lose the uninitiated. And the fact that if you don't understand DNS, the results won't really help you.

My advice: learn the basics of SPF, DKIM, and DMARC. Then, MxToolbox becomes your best friend for diagnosing problems. Use it systematically when configuring a new sending domain.

Why add it to your stack?

The essential technical diagnostic tool when something is wrong with deliverability. First reflex when emails stop arriving.

What you can do with it

  • 1Verify that your email DNS records (SPF, DKIM, DMARC) are correctly configured
  • 2Test if your domain or IP is on blacklists
  • 3Diagnose your mail server configuration problems
  • 4Validate a new sending domain's configuration

What it does

  • SPF, DKIM, DMARC verification
  • Blacklist testing
  • MX records analysis
  • Complete DNS diagnostics
  • Monitoring (Pro version)

How much?

Starting at 0

Very powerful free plan, Pro at $139/year for monitoring.

The detailed verdict

Do I really need this?

When you have a deliverability problem, it's often the first tool to pull out. Essential in the toolkit.

Does it play nice with my stack?

Not really any integrations, it's a manual diagnostic tool. You come, you test, you leave.

Is it easy to pick up?

Easy to use if you understand DNS concepts. Otherwise, results can be cryptic.

Is the UX any good?

The interface is austere and technical. It's made for people who know what they're looking for. No frills.

Is it worth it?

The free plan does 90% of the work. Pro at $139/year is only useful if you need continuous monitoring. Excellent value for money.

What I like

  • Diagnose deliverability and DNS configuration problems
  • Check blacklists and validate SPF DKIM DMARC
  • Sys admins and technical growth engineers who understand DNS

What I like less

  • Non-technical marketers as it's very technical
  • Those who just want to send emails without understanding DNS
  • Austere interface that can lose the uninitiated

Need more details or help building your ideal stack?

Visit official siteGet advice