SSL-Tools

SSL check results of otto-kuehne-schule.de

NEW You can also bulk check multiple servers.

Discover if the mail servers for otto-kuehne-schule.de 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 Sat, 26 Sep 2026 00:30:24 +0000

The mailservers of otto-kuehne-schule.de can be reached through a secure connection.

Servers

Incoming Mails

These servers are responsible for incoming mails to @otto-kuehne-schule.de addresses.

Hostname / IP address Priority STARTTLS Certificates Protocol
rx01.otto-kuehne-schule.net
91.26.120.229
 10
supported
*.otto-kuehne-schule.net
DANE
missing
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
3 s

Outgoing Mails

We have not received any emails from a @otto-kuehne-schule.de address so far. Test mail delivery

Certificates

First seen at:

CN=*.otto-kuehne-schule.net

Certificate chain
Subject
Common Name (CN)
  • *.otto-kuehne-schule.net
Alternative Names
  • *.otto-kuehne-schule.net
  • otto-kuehne-schule.net
Issuer
Country (C)
  • US
Organization (O)
  • DigiCert Inc
Organizational Unit (OU)
  • www.digicert.com
Common Name (CN)
  • RapidSSL TLS RSA CA G1
validity period
Not valid before
2026-09-11
Not valid after
2027-03-28
This certifcate has been verified for the following usages:
  • Digital Signature
  • Key Encipherment
  • TLS Web Server Authentication
Fingerprints
SHA256
D9:A8:40:75:26:54:1E:ED:62:FE:95:95:22:4E:15:98:92:FC:DC:CA:B6:E1:CD:38:51:A1:0F:8A:33:B2:0A:22
SHA1
F4:0B:33:B7:53:5D:EF:E4:D2:5D:50:FF:C6:22:09:93:77:E6:0E:98
X509v3 extensions
authorityKeyIdentifier
  • keyid:0C:DB:6C:82:49:0F:4A:67:0A:B8:14:EE:7A:C4:48:52:88:EB:56:38
subjectKeyIdentifier
  • 7C:C5:DC:CC:00:41:D5:0F:F6:BB:FB:3B:66:D8:30:F0:47:DB:36:D1
certificatePolicies
  • Policy: 2.23.140.1.2.1
  • CPS: http://www.digicert.com/CPS
crlDistributionPoints
  • Full Name:
  • URI:http://cdp.rapidssl.com/RapidSSLTLSRSACAG1.crl
authorityInfoAccess
  • OCSP - URI:http://status.rapidssl.com
  • CA Issuers - URI:http://cacerts.rapidssl.com/RapidSSLTLSRSACAG1.crt
ct_precert_scts
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : 4C:63:DC:98:E5:9C:1D:AB:88:F6:1E:8A:3D:DE:AE:8F:
  • AB:44:A3:37:7B:5F:9B:94:C3:FB:A1:9C:FC:C1:BE:26
  • Timestamp : Sep 11 13:20:33.416 2026 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:45:02:20:46:80:C1:F2:9D:CC:FB:82:C8:B5:F4:6E:
  • 3F:50:F8:77:31:04:6B:38:4B:9B:93:2C:52:29:F4:D6:
  • C3:70:43:D7:02:21:00:D8:21:FB:35:F3:CD:5E:E7:A8:
  • 9E:1C:52:4E:43:27:E4:EC:AD:74:B5:EA:DA:DA:07:7E:
  • 19:2F:18:A9:C5:D0:8B
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : D6:D5:8D:A9:D0:17:53:F3:6A:4A:A0:C7:57:49:02:AF:
  • EB:C7:DC:2C:D3:8C:D9:F7:64:C8:0C:89:19:1E:9F:02
  • Timestamp : Sep 11 13:20:33.403 2026 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:46:02:21:00:EE:45:01:5F:BD:40:9D:BF:9A:A4:1B:
  • 79:BB:46:DC:FB:DD:E5:46:B2:69:30:AD:61:80:0B:F7:
  • 03:D8:D7:C1:94:02:21:00:F3:84:3D:52:A5:FF:63:5C:
  • 77:B9:57:84:2F:85:D6:23:F6:0B:71:C2:02:A4:94:C1:
  • 59:72:E1:38:63:AC:80:69
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : 44:C2:BD:0C:E9:14:0E:64:A5:C9:4A:01:93:0A:5A:A1:
  • BB:35:97:0E:00:EE:11:16:89:68:2A:1C:44:D7:B5:66
  • Timestamp : Sep 11 13:20:33.479 2026 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:45:02:21:00:B1:BC:4F:59:80:7B:5F:67:B8:83:6B:
  • BF:24:1F:C8:BA:03:6D:57:D8:EE:51:EB:85:20:4E:2D:
  • C2:50:54:1C:D7:02:20:26:C4:89:38:FA:C0:AA:79:B6:
  • E6:60:E6:F4:0A:AB:89:EA:DF:B1:90:A5:4F:13:AD:B1:
  • 66:7E:A8:D0:70:DA:5A