SSL-Tools

SSL check results of proton.me

NEW You can also bulk check multiple servers.

Discover if the mail servers for proton.me can be reached through a secure connection.

To establish a secure connection a mail server has to offer STARTTLS (SSL), a trustworthy SSL certificate, support for the Diffie-Hellman-Algorithm to guarantee Perfect Forward Secrecy and must not be vulnerable against the Heartbleed attack. Futhermore we recommend using end-to-end encryption with GnuPG.

Summary

JSON Refresh

Report created Fri, 29 Aug 2025 02:53:01 +0000

The mailservers of proton.me can be reached through a secure connection.

Servers

Incoming Mails

These servers are responsible for incoming mails to @proton.me addresses.

Hostname / IP address Priority STARTTLS Certificates Protocol
mail.protonmail.ch
185.70.42.128
 10
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
19 s
mail.protonmail.ch
185.205.70.128
 10
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
24 s
mail.protonmail.ch
176.119.200.128
 10
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
37 s
mailsec.protonmail.ch
185.205.70.129
 20
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
2 s
mailsec.protonmail.ch
176.119.200.129
 20
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
2 s
mailsec.protonmail.ch
185.70.42.129
 20
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
2 s

Outgoing Mails

We have not received any emails from a @proton.me address so far. Test mail delivery

Certificates

First seen at:

CN=protonmail.com

Certificate chain
  • protonmail.com
    • remaining
    • 4096 bit
    • sha256WithRSAEncryption
      • R10
        • remaining
        • 2048 bit
        • sha256WithRSAEncryption
          • ISRG Root X1 (Certificate is self-signed.)
            • remaining
            • 4096 bit
            • sha256WithRSAEncryption
Subject
Common Name (CN)
  • protonmail.com
Alternative Names
  • *.pm.me
  • *.protonmail.ch
  • *.protonmail.com
  • *.protonvpn.ch
  • *.protonvpn.com
  • protonmail.com
Issuer
Country (C)
  • US
Organization (O)
  • Let's Encrypt
Common Name (CN)
  • R10
validity period
Not valid before
2025-08-08
Not valid after
2025-11-06
This certifcate has been verified for the following usages:
  • Digital Signature
  • Key Encipherment
  • TLS Web Server Authentication
  • TLS Web Client Authentication
Fingerprints
SHA256
65:F2:B7:B0:07:8D:91:C3:57:AF:4A:54:B6:49:16:21:DD:E6:A9:98:32:27:AD:B0:AE:39:E7:E9:A7:6D:B1:87
SHA1
7D:DA:8E:96:2F:14:DD:8F:F9:2D:CC:FC:DC:B3:C9:D2:93:63:62:DB
X509v3 extensions
subjectKeyIdentifier
  • F1:A2:0A:FF:29:EF:F8:78:84:E8:07:0C:E0:56:8A:76:64:D2:2B:A5
authorityKeyIdentifier
  • keyid:BB:BC:C3:47:A5:E4:BC:A9:C6:C3:A4:72:0C:10:8D:A2:35:E1:C8:E8
authorityInfoAccess
  • CA Issuers - URI:http://r10.i.lencr.org/
certificatePolicies
  • Policy: 2.23.140.1.2.1
crlDistributionPoints
  • Full Name:
  • URI:http://r10.c.lencr.org/23.crl
ct_precert_scts
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : CC:FB:0F:6A:85:71:09:65:FE:95:9B:53:CE:E9:B2:7C:
  • 22:E9:85:5C:0D:97:8D:B6:A9:7E:54:C0:FE:4C:0D:B0
  • Timestamp : Aug 8 14:13:19.003 2025 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:44:02:20:00:AA:1A:73:DF:42:F7:F1:59:7C:D2:F4:
  • 52:12:A8:06:5B:83:B6:6F:8E:AE:1E:71:21:5A:01:CB:
  • E4:8D:AC:A5:02:20:29:B2:C7:5C:20:58:E9:96:F7:07:
  • 4E:EB:25:BE:35:2F:F8:B3:E8:85:B4:FD:31:1C:F3:6B:
  • 4C:6D:FF:CF:E5:37
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : DD:DC:CA:34:95:D7:E1:16:05:E7:95:32:FA:C7:9F:F8:
  • 3D:1C:50:DF:DB:00:3A:14:12:76:0A:2C:AC:BB:C8:2A
  • Timestamp : Aug 8 14:13:19.059 2025 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:45:02:20:63:E4:6C:B2:15:83:41:06:D4:E6:6D:B9:
  • AD:AD:A8:B1:84:DD:DA:2E:21:12:4B:9C:B6:73:AB:EB:
  • 1D:A1:26:5C:02:21:00:9F:7C:D2:38:66:F4:3E:B9:96:
  • 84:94:E6:43:1A:38:2E:41:72:92:ED:A0:61:DF:B6:06:
  • 83:E7:B1:24:60:CD:3D

DANE

DNS-based Authentication of Named Entities (DANE) is a protocol to allow X.509 certificates to be bound to DNS using TLSA records and DNSSEC.

Name Options DNSSEC Matches
_25._tcp.mail.protonmail.ch
  • DANE-EE: Domain Issued Certificate
  • Use subject public key
  • SHA-256 Hash
valid
valid
_25._tcp.mail.protonmail.ch
  • DANE-EE: Domain Issued Certificate
  • Use subject public key
  • SHA-256 Hash
valid
—
_25._tcp.mailsec.protonmail.ch
  • DANE-EE: Domain Issued Certificate
  • Use subject public key
  • SHA-256 Hash
valid
valid
_25._tcp.mailsec.protonmail.ch
  • DANE-EE: Domain Issued Certificate
  • Use subject public key
  • SHA-256 Hash
valid
—