Check the DKIM keys of any domain
Results for
proton.me
Email authentication
1 warning
Warning- SPF
- Pass:~all (soft fail), 2 of 10 lookups
- DMARC
- Warning:p=quarantine
- DKIM
- Pass:2 keys: protonmail, protonmail2
- MTA-STS
- Pass:Published
- TLS reporting
- Pass:Published
- BIMI
- Note:Declined
- Mail servers
- mail.protonmail.ch, mailsec.protonmail.ch
DKIM keys
24 selectors checked
Pass- protonmail._domainkey.proton.mePass:2048-bit RSA
Show record
v=DKIM1;k=rsa;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAn46zCm3zHBmS1zePKxA+RIXw41Nu6l91NpLLBnWnrcZ35H/843XNWPZEQ0OgGwx/yqTXETMLXIDjGEWlK1E1mpdguqu+3s7SuIHoo5+i6mgyxJguljkwc3dk8ojnJ6VVUPnDh5GJArkAhXxEb1aOK1BVGM0yDlmYdmaOfd48qcx5iODP/MFc8pivfxEXTIL+aUz7+X69lMiwUSHpWYL3/a5X3nLD0zEntxv08xs8J/rpuRg4v+OXEOhcNvhkeiRZqJBdpJTkoEZfGvdTct+U0YYC69NW0ClUcKio2uDPmxU1xvfvHbSTW2gHYk8RpYZaxLACULdMo+Vt4Na/oIR+swIDAQAB;
- protonmail2._domainkey.proton.mePass:2048-bit RSA
Show record
v=DKIM1;k=rsa;p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzyzKjxw9soyR/PtOaHGV2qeOR63FVUMlRr2ssw6yZQGea4O3DzioVtwQMjXhqkLSnthca9zIyInBEcWXbC2LwRWX0vXJrULQpFtY1anvBebUJgbX9W2TJUW8seVoVVcKk0DF4iENEtsWNPBpuGKdx1BPpN4OujjWFs7RN4oIMHnJpSIlxzX9hT8mwdlUuKA4GsOOBg8zpXQIeJy8jDWj2xrmd6GxGsSCBD4mRrqwscSWU+RN6vyUon8wT2b3HujvCCRUhIrd40tMeT9clyl7IZSTJu5M7q0+s/favDSKiyIMBG4Walzr5OuFMl2eEGwDp45s3jQZfjHlczjCeyjmEwIDAQAB;
Selectors we checked (24)
- selector1
- selector2
- default
- dkim
- k1
- k2
- k3
- s1
- s2
- smtp
- mx
- mandrill
- mxvault
- protonmail
- protonmail2
- fm1
- fm2
- sig1
- zmail
- kl
- s1024
- s2048
To check another selector, enter it as selector._domainkey.proton.me.
SPF record
2 of 10 DNS lookups
Passv=spf1 include:_spf.protonmail.ch ~all
- Uses 2 of 10 DNS lookups.
- Ends in ~all (soft fail), so receivers accept mail from unlisted servers but mark it as suspicious.
Includes
2 domains
- include:_spf.protonmail.ch2 lookups
- include:_spf2.protonmail.ch1 lookup
DMARC record
_dmarc.proton.me
Warningv=DMARC1; p=quarantine; fo=1; aspf=s; adkim=s;
- Policy p=quarantine: receivers send mail that fails DMARC to spam.
- No rua= address, so nobody receives the reports that show who sends mail as proton.me.
- Policy
- quarantine (send to spam)
- Subdomain policy
- quarantine (send to spam)
- Percentage
- 100%
- Aggregate reports
- None
- Failure reports
- None
- DKIM alignment
- Strict
- SPF alignment
- Strict
MTA-STS, TLS reporting and BIMI
Optional records
MTA-STS
v=STSv1; id=190906205100Z;
- MTA-STS is on (policy id 190906205100Z). The policy file lives at https://mta-sts.proton.me/.well-known/mta-sts.txt.
TLS reporting
v=TLSRPTv1; rua=https://reports.proton.me/reports/smtptls
- TLS reports go to https://reports.proton.me/reports/smtptls.
BIMI
v=BIMI1; l=; a=;
- The BIMI record has no logo (empty l=), so it declines BIMI.
Run this lookup from code
The API returns this result as JSON. The free plan includes 100 API calls per month.
curl "https://hostingchecker.online/api/v1/email-auth?query=proton.me" \
-H "Authorization: Bearer YOUR_API_KEY"How it works
How DKIM works
The sending server hashes the message body and selected headers, signs the hash with its private key and adds a DKIM-Signature header. The header names the signing domain (d=) and the selector (s=). The receiver fetches the public key from DNS and verifies the signature.
A valid signature proves the message was not changed and was signed by someone with access to the domain's DNS. For DMARC to pass on DKIM, the signing domain must match the domain in the visible From address.
- v
- Version, always DKIM1
- k
- Key type: rsa (default) or ed25519
- p
- The public key. Empty means the key is revoked
- t
- Flags: y for testing, s for no subdomains
FAQ
DKIM checker FAQ
Common questions about DKIM keys and selectors.
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Check the DKIM keys of any domain
Find the DKIM keys of any domain. We look up common selectors or the one you enter, and check the key type, key length and testing flag.