SSL-Tools

SSL check results of protonmail.ch

NEW You can also bulk check multiple servers.

Discover if the mail servers for protonmail.ch 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

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Report created Mon, 17 Mar 2025 17:39:38 +0000

The mailservers of protonmail.ch can be reached through a secure connection.

Servers

Incoming Mails

These servers are responsible for incoming mails to @protonmail.ch addresses.

Hostname / IP address Priority STARTTLS Certificates Protocol
mail.protonmail.ch
185.70.42.128
 5
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
 5
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
14 s
mail.protonmail.ch
176.119.200.128
 5
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
8 s
mailsec.protonmail.ch
185.70.42.129
 10
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
 10
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
8 s
mailsec.protonmail.ch
185.205.70.129
 10
supported
protonmail.com
DANE
valid
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
8 s

Outgoing Mails

We have received emails from these servers with @protonmail.ch sender addresses. Test mail delivery

Host TLS Version & Cipher
mail-40138.protonmail.ch (185.70.40.138)
TLSv1.3 TLS_AES_256_GCM_SHA384
mail-40132.protonmail.ch (185.70.40.132)
TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384
mail-40131.protonmail.ch (185.70.40.131)
TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384
mail-40130.protonmail.ch (185.70.40.130)
TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384

Certificates

First seen at:

CN=protonmail.com

Certificate chain
  • protonmail.com
    • remaining
    • 4096 bit
    • sha256WithRSAEncryption
      • R11
        • 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)
  • R11
validity period
Not valid before
2025-02-15
Not valid after
2025-05-16
This certifcate has been verified for the following usages:
  • Digital Signature
  • Key Encipherment
  • TLS Web Server Authentication
  • TLS Web Client Authentication
Fingerprints
SHA256
64:0F:88:AC:8A:ED:70:D6:35:A2:40:83:4B:F2:29:D6:EF:6E:1D:05:F8:F6:FA:D6:E4:E1:E7:99:35:9D:90:04
SHA1
72:32:F7:D2:80:EF:30:BB:EB:25:EE:92:FC:2A:60:20:72:E7:A8:0E
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:C5:CF:46:A4:EA:F4:C3:C0:7A:6C:95:C4:2D:B0:5E:92:2F:26:E3:B9
authorityInfoAccess
  • OCSP - URI:http://r11.o.lencr.org
  • CA Issuers - URI:http://r11.i.lencr.org/
certificatePolicies
  • Policy: 2.23.140.1.2.1
ct_precert_scts
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : 7D:59:1E:12:E1:78:2A:7B:1C:61:67:7C:5E:FD:F8:D0:
  • 87:5C:14:A0:4E:95:9E:B9:03:2F:D9:0E:8C:2E:79:B8
  • Timestamp : Feb 15 14:13:29.384 2025 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:45:02:21:00:E1:B2:B2:9F:49:65:78:9B:AC:F4:5C:
  • 04:68:72:41:A1:D5:E4:13:46:DD:4E:24:F7:13:57:5C:
  • B3:7C:FD:E3:E1:02:20:22:DD:66:FA:8D:6E:58:25:9F:
  • 4B:D2:25:36:81:71:99:1D:5B:50:2F:54:43:5D:E0:51:
  • 6A:4A:85:9C:95:82:03
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : A2:E3:0A:E4:45:EF:BD:AD:9B:7E:38:ED:47:67:77:53:
  • D7:82:5B:84:94:D7:2B:5E:1B:2C:C4:B9:50:A4:47:E7
  • Timestamp : Feb 15 14:13:29.402 2025 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:45:02:20:6D:F2:36:34:A6:4C:9B:E8:04:9D:6F:B7:
  • 4D:C8:40:B9:11:46:D4:B5:FA:E4:63:53:84:29:2F:83:
  • A1:8D:C4:38:02:21:00:CE:37:D1:6D:F8:AE:4E:70:33:
  • 8A:7F:D2:F8:50:76:10:BC:37:4C:AF:DE:65:9A:55:CF:
  • 97:41:C4:38:19:74:4A

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