DNS & deliverability platform

Everything you need to verify your DNS zones and email authentication

Resolve, audit and fix DNS, SPF, DKIM, DMARC and BIMI records from a single dashboard with easy-to-use diagnostics.

Run a DNS lookupDMARC inspector
Domains analysed
48K+

Aggregated data since 2025

DNS queries processed
12M/mo
SPF/DKIM/DMARC reports generated
260K+
Active monitors
8K+

Alerts sent as soon as a difference or latency anomaly is detected

Core engines

Three modules at the heart of CaptainDNS to troubleshoot zones, secure authentication and keep campaigns out of spam folders.

Universal DNS lookup

Instant A, AAAA, MX, TXT and CNAME resolutions across 18 resolvers with latency and RCODE insights.

Start a lookup

Deliverability audit

Full SPF, DKIM, DMARC, MX, TLS, PTR and DNSSEC analysis for every sending domain you manage.

Audit a domain

SPF/DKIM/DMARC analyzers

Hardened parsers, policy suggestions and lookup budgeting to prevent blocks and maximise alignment.

Explore analyzers
Productivity

A complete suite to control every deliverability signal

Combine DNS diagnostics, authentication checks and automation to keep your campaigns in the inbox.

Product screenshot
DNS Lookup

See the entire DNS matrix at once

Compare UDP, TCP and DoH answers, monitor latency and export every iteration.

350 ms
Median latency observed
  • Parallel resolutions across 18 major resolvers
  • Export histories as CSV or JSON
Deliverability audit

Catch blockers before your campaigns ship

SPF, DKIM, DMARC, MX, TLS and PTR checklist with automatic prioritisation.

  • Compliance score with guided fixes
  • Alignment alerts for SPF and DKIM
  • DNSSEC and DANE validation
SPF Lab

Debug complex SPF records

Advanced syntax analysis, visual include tree and DNS lookup budgeting.

  • Visual recursive include tree
  • Lookup count and remaining budget
DMARC

Prepare confident DMARC policies

Validate tags, simulate policy impact and get recommendations to move into enforcement.

  • Instant tag and URI validation
  • Policy guidance from p=none to reject
Automation

APIs and scheduled workflows

Plug CaptainDNS into your CI/CD, export reports and trigger incident alerts automatically.

  • REST API, webhooks and S3 pipelines
  • BigQuery exports and custom dashboards

Latest articles

Blog

CaptainDNS · November 27, 2025

Behind the scenes of the CaptainDNS MCP

How we wired CaptainDNS to AIs through MCP: architecture, HTTP+SSE transport, JSON-RPC, 424 errors, timeouts, and what we learned along the way.

  • #MCP
  • #Architecture
  • #DNS
  • #Email
  • #AI integrations

CaptainDNS · November 21, 2025

An MCP for CaptainDNS?

Before plugging CaptainDNS into AIs, you need to understand what the Model Context Protocol (MCP) is and what it really enables. A short MCP ABC, then first steps for CaptainDNS.

  • #MCP
  • #AI
  • #DNS
  • #Email
  • #Architecture
About

Making deliverability transparent for the teams that run email

We build CaptainDNS to give marketing and SRE teams complete visibility into DNS configuration and deliverability signals. Every tool explains what must be fixed and why it matters.

Our distributed infrastructure mirrors the reality of your recipients. Know whether resolvers in Frankfurt, Sydney or Montreal see the same answer, and get alerted as soon as a divergence appears.

Global resolvers monitored
18
Uptime over 12 months
99.99%
Support response time
< 24 h
Continents covered
4
FAQ

Frequently asked questions

Stay in control of DNS and deliverability with actionable explanations. Here are the answers to the most common requests.

Does the DNS lookup run from multiple regions?
Yes, each query runs across 18 resolvers on four continents so you see what your recipients experience.
Can I export my audit results?
Reports and histories download as CSV, JSON and PDF. Pro plans can also push exports to S3 or BigQuery.
How do monitoring alerts work?
Pick a domain and record type to watch: we automatically query 18 resolvers and notify you by email or webhook as soon as a difference or latency anomaly appears.
How do you handle oversized SPF records?
SPF Lab calculates lookup counts, highlights cascading includes and suggests safe flattening strategies.
Can I share a saved request?
Yes. Every stored request includes a shareable link with sensitive inputs redacted, and you can turn it into a monitor in one click.
Is there an API?
Absolutely. Every key capability is available through a REST API with token authentication and webhooks for alerts.
Is the platform a good fit for agencies?
Multi-brand organisations are supported with shared access, folders and per-client quotas.
Do you offer a free trial?
All tools can be launched for free. Paid plans unlock history, automated exports and priority support.

Launch your next audit in seconds

Try it for free, then upgrade to the plan that matches your volume when you're ready.

Run a DNS domain audit