checkdmarc
A Python module, command line utility, and web application for validating SPF and DMARC DNS records.
Sponsors
This project is maintained by one developer. Please consider sponsoring my work if you or your organization benefit from it.
Features
- API, CLI, and web interfaces
- Can test multiple domains at once
- CLI output in JSON or CSV format
- DNSSEC validation
- SPF
- Record validation
- Counting of DNS lookups and void lookups
- Counting of lookups per mechanism
- DMARC
- Validation and parsing of DMARC records
- Shows warnings when the DMARC record is made ineffective by
spvalues, or by use of thepct/rf/ritags that were removed in RFC 9989 - Checks for authorization records on reporting email addresses
- BIMI
- Validation of the mark format and certificate against the Minimum Security Requirements for Issuance of Mark Certificates
- Parsing of the mark certificate
- MX records
- Preference
- IPv4 and IPv6 addresses
- Optional STARTTLS and TLS testing (pass
--check-mx-tls) - Use of DNSSEC/TLSA/DANE to pin certificates
- MTA-STS
- SMTP TLS reporting
- Record and policy parsing and validation
- SOA record parsing
- Nameserver listing
Docker support
- Build the image using
docker build . -t checkdmarc - Use the image with a command like
docker run --rm checkdmarc google.nl
1 maintainer
Release files for checkdmarc 6.0.2
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| checkdmarc-6.0.2.tar.gz | 103.2 kB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| checkdmarc-6.0.2-py3-none-any.whl | Python 3 | none | any | Details |
Total release size:218.0 kB
Release files / checkdmarc-6.0.2.tar.gz
| Download URL | checkdmarc-6.0.2.tar.gz |
|---|---|
| Size | 103.2 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
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|
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BLAKE2b-256 checksum How to use checksums |
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| Upload date | |
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Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.14
|
Provenance
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Signed by GitHub Actions, verified by PyPI on Sep 17, 2026.
Transparency logRelease files / checkdmarc-6.0.2-py3-none-any.whl
| Download URL | checkdmarc-6.0.2-py3-none-any.whl |
|---|---|
| Size | 114.8 kB |
| Tags | Python 3 |
|
SHA-256 checksum How to use checksums |
d7cb5de290dd0d57f0a59b3571223f8db7de0fe6c3708114de7da17068b01fa9
|
|
BLAKE2b-256 checksum How to use checksums |
b0b5f0d17e0c3316cc26a525695f6ed1bae44eb86c2b367765007bc6dabf3874
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.14
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Sep 17, 2026.
Transparency log
