Your emails are landing in spam. You just don't know it yet.

InboxOK monitors SPF, DKIM, DMARC, and blacklists — 24/7. Get alerted with the exact fix before it costs you a customer.

Start Monitoring Free

Free forever for 1 domain · No credit card required · 60-second setup

“I run a newsletter for another project. My DNS records were misconfigured and nothing told me — I only found out by manually inspecting raw headers.”

— InboxOK's founder

Email deliverability is a silent killer

You send receipts, password resets, order confirmations — and assume they arrive. But by the time a customer complains they never got their invoice, you've already lost trust, and maybe the sale.

Auth records break silently
A DNS change or an expired key can quietly break SPF, DKIM, or DMARC — nothing tells you.
Domains get blacklisted
Your IP or domain lands on a blacklist without any notification to the sender.
Messages route to spam
Gmail and Outlook don't send you a receipt. Zero visibility into where mail actually lands.

InboxOK is a robot watchdog for your email health

Most tools give you a point-in-time report. InboxOK gives you trending health over time — so you see problems forming before they become crises.

Authentication monitoring
Automated checks every 24 hours across SPF, DKIM, and DMARC. If your mail passport breaks, you know within hours — not when customers start complaining.
Blacklist surveillance
Pro+
Monitors 14 major DNSBLs — Spamhaus, Barracuda, SURBL, URIBL, and more. Get alerted within hours of a new listing, with delisting guidance.
Inbox placement testing
Coming soon
Sends diagnostic probe emails through Mail-Tester and reports a spam score — inbox, spam, or in between. Not a simulated guess — a real deliverability test.

Simple pricing. Predictable billing.

Flat account pricing with tiered domain limits. Your bill doesn't spike because you ran a Black Friday campaign.

MonthlyAnnual (2 months free)
Free

$0/mo

  • 1 domain
  • Daily checks
  • Email alerts
  • Blacklist monitoring
  • Inbox placement testing (coming soon)
  • Webhooks
  • API access
  • Slack alerts
  • Priority support
Start Free
Basic

$20/mo

Billed annually at $240/yr — 2 months free

  • 5 domains
  • Daily checks
  • Email alerts
  • Blacklist monitoring
  • Inbox placement testing (coming soon)
  • Webhooks
  • API access
  • Slack alerts
  • Priority support
Start Basic
Most Popular
Pro

$65.83/mo

Billed annually at $790/yr — 2 months free

  • 10 domains
  • Daily checks + hourly on-demand re-checks
  • Email alerts
  • Blacklist monitoring
  • Inbox placement testing (coming soon)
  • Webhooks
  • API access
  • Slack alerts
  • Priority support
Start Pro
Business

$165.83/mo

Billed annually at $1,990/yr — 2 months free

  • 50 domains
  • Daily checks + unlimited on-demand re-checks
  • Email alerts
  • Blacklist monitoring
  • Inbox placement testing (coming soon)
  • Webhooks
  • API access
  • Slack alerts
  • Priority support
Start Business

Annual billing = 2 months free on all paid tiers.

Built solo with AI tools. In the open.

InboxOK was built solo with Claude Code and Deepseek — from zero to production. We eat our own dogfood: the same API you integrate with is the one that powers our dashboard. No black boxes.

Frequently asked questions

⌘K

Yes. One domain, forever, no credit card, no trial clock — and it includes daily checks, the dashboard, email alerts, and the daily digest. We make money when you grow into paid tiers, not by baiting you into a trial.

Placement testing (coming soon on Pro and Business) sends tiny probe messages from our own infrastructure to Mail-Tester test addresses and reports a spam score — inbox, spam, or in between. We never touch your mailboxes, your credentials, or your email content.

No. We only send notifications to you — alerts and the daily digest — plus diagnostic probe messages when placement testing runs. We never touch your customer lists, your SMTP credentials, or your actual outbound mail.

Your provider watches their own IP reputation. They don't watch your DNS records. If someone on your team accidentally breaks your SPF record while setting up a landing page tool, your provider will keep sending mail into a black hole. We catch that.

Zero. We query public DNS and run everything through our own infrastructure. Your servers, database, and API response times are never touched.

Every plan is scanned automatically every day — and new domains are checked the moment you add them. When a record fails, you get an alert with the exact change we detected and copy-paste fix instructions. Pro and Business can also re-check on demand: hourly and unlimited, respectively.

Yes — on Pro and Business. Every domain, check, score, blacklist hit, and alert is available as structured JSON, with interactive docs at api.inboxok.com/docs. Pipe it into Slack, PagerDuty, or your own webhook in about 60 seconds.

No. We don't have access to them. We only store your domain's public DNS records, blacklist statuses, and check history — never your mailbox contents or credentials.

Stop guessing. Start knowing.

Add your domain. Get your first health report in 60 seconds. Free forever for 1 domain.