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ProbeKit vs MxToolbox

If you’re looking for an MxToolbox alternative, ProbeKit runs the everyday DNS, email and blacklist checks free, with no account needed, and adds a few things of its own. This page sticks to what ProbeKit does; for MxToolbox’s current features and prices, see its own site.

Where MxToolbox is strong

MxToolbox has a long track record and wide adoption among admins.

Why admins look for an alternative

  • Published pricing: Free, Pro $15/month ($12 billed annually) and MSP $79/month ($65 annually), all on one page.
  • Free monitoring: 3 monitors on 2 domains with email and webhook alerts, plus hosted DMARC reports for 1 domain, on the free plan.
  • Bounce diagnosis: Paste a bounce or SMTP error: Diagnose names the cause and the fix, then runs the checks that confirm it.
  • AI Explain & Fix: A plain-English verdict on any result, with the exact DNS records to paste.
  • MSP white-label: Clients, white-label PDF reports and status pages, and read-only client logins.
  • Passkeys: Sign in with a passkey (Touch ID, Face ID, Windows Hello) or a password.
  • API: A REST API with an OpenAPI spec; 100 requests a day on the free plan.

Every lookup stays free; paid plans add faster monitoring, more alert channels and MSP features.

Pick a check, or type a prefix like spf:

FAQ

Is ProbeKit free?
Yes. Every lookup is free and needs no account. The free plan adds 3 monitors on 2 domains, hosted DMARC reports for 1 domain and 100 API requests a day.
Do I need an account?
No. Every lookup runs without one. A free account adds monitors and alerts, saved results, hosted DMARC reports, and more Diagnose runs and AI explanations each day.
Can I monitor blacklists?
Yes. A blacklist monitor checks an IP or domain against about 40 DNS blocklists on a schedule and alerts you by email or webhook when it gets listed. The free plan checks daily; Pro and MSP check hourly.
Is there an API?
Yes: a REST API with an OpenAPI spec, using API keys from your account. The free plan includes 100 requests a day, Pro 5,000 and MSP 50,000.
Does ProbeKit replace MxToolbox?
For everyday MX, SPF, DKIM, DMARC, DNS, blacklist, SMTP and TLS checks, many admins can use ProbeKit instead. Before switching, compare the specific tools you rely on with MxToolbox’s own site; this page doesn’t describe MxToolbox’s features.

MxToolbox is a trademark of its owner. ProbeKit is not affiliated with MxToolbox.