checkdmarc

v6.0.4Verified publisher

Checks a domain's SPF, DMARC, MX, BIMI and DNSSEC records and reports problems

Community-packaged from github.com/domainaware/checkdmarc: the registry's community pins the upstream release; the tool is its authors' work. Maintain that project? Claim this package.

Run

TerminalAgent

Through ot mcp, an agent calls run_tool with this; ot asks you before anything that goes online or touches a target. Set it up: ot mcp install claude (or cursor, vscode, codex, gemini).

{"tool":"osintverse-community/checkdmarc","target":"example.com","input_type":"domain"}

Or just say: "Run osintverse-community/checkdmarc on example.com with OTInstaller." The registry's read-only MCP server at api.otinstaller.com/mcp can find tools without installing anything.

ot run osintverse-community/checkdmarc d:example.com --format table

ot install osintverse-community/checkdmarc

Python wheel, run in a read-only container (Docker optional with --native) · network allowed · no key · up to 5 min. The first ot run installs the tool after asking once. The example value is the registry's own test input, so this command has run. Drop --format table for JSON.

Don't have ot? Install it in one line

macOS / LinuxWindows

curl -fsSL https://get.otinstaller.com/ot | sh

What this script does

Downloads the latest ot release for your machine from GitHub Releases.
Checks its SHA-256 against checksums.txt, and the Ed25519 signature on that file against the key built into the script.
Puts ot in /usr/local/bin or ~/.local/bin. Nothing else is written. Read the script.

irm https://get.otinstaller.com/ot.ps1 | iex

What this script does

Downloads the latest ot release for your machine from GitHub Releases.
Checks its SHA-256 against checksums.txt, and the Ed25519 signature on that file against the key built into the script.
Puts ot in %LOCALAPPDATA%\Programs\ot, and adds it to your PATH. Nothing else is written. Read the script.

Evidence

Security tab →

Pinnedwheel sha256:5b17606a…428bc2 from PyPI. ot re-hashes the file after download and refuses a mismatch.
Signedby pypi:GitHub:domainaware/checkdmarc/release.yml via pypi.org, verified by the registry on 20 Oct 2026. ot checks the same identity before every install and refuses another signer.
Scanned20 Oct 2026: 0 critical, 0 high, 5 medium, 1 low vulnerabilities; 0 embedded secrets, 0 malware heuristics; SBOM with 28 packages.
Workssmoke test passed on 20 Oct 2026 (exit 0 in 2.5 s, offline sandbox); the nightly health check passed (today).
Backed upa copy of this wheel is kept by the registry. If PyPI removes it, ot downloads the copy and checks the same hash.
Reviewedosintverse-community is a verified publisher: the registry confirmed who runs it, and a person reviewed its first release against the acceptable-use rules.

What you get back

Result envelope →

{
  "envelope": 1,
  "tool": "osintverse-community/checkdmarc@6.0.4",
  "runtime": "pipx",
  "input": {
    "domain": "example.com"
  },
  "started_at": "2026-10-21T09:00:00Z",
  "duration_ms": 4100,
  "exit_code": 0,
  "entities": [
    {
      "type": "dns_record",
      "value": "example.com A 192.0.2.1"
    },
    {
      "type": "domain",
      "value": "example.com"
    }
  ],
  "warnings": []
}

Every tool returns this shape, shaped here from what this tool declares it finds. --format table to read it; ot extract and ot auto to continue.

checkdmarc (community package)

This repository packages github.com/domainaware/checkdmarc for the OTInstaller Registry as osintverse-community/checkdmarc. The tool is the work of its authors, under the Apache-2.0 license; this repository only holds the manifest and release workflow.

Report problems with the tool upstream, and problems with the packaging here. If you maintain the upstream project and want to publish it yourself, open an issue or run ot claim osintverse-community/checkdmarc: the package is transferred to you.

It installs the upstream project's own release from PyPI, pinned by version and hash; nothing here is rebuilt.

ot run osintverse-community/checkdmarc --domain …

Packaged version: 6.0.4.

Guides using this tool

Domain investigation playbook

DNS, subdomains, certificates, history and look-alikes of a domain, passively first

About domain
intermediate

Verified publisher

Email investigation playbook

Trace a suspicious message and find where an address is registered, without alerting its owner

About email
beginner

Verified publisher

What next

checkdmarc finds dns record, domain. Tools that take those:

dns record → 10 tools domain → 9 tools ot auto, with a saved result

Other domain tools

All domain tools →

Alternatives to checkdmarc that also take a domain; ot auto runs every installed one on the same value.