SSL-Tools

SSL check results of serv301.de

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Discover if the mail servers for serv301.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

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Report created Sat, 09 May 2026 20:46:23 +0000

The mailservers of serv301.de can be reached through a secure connection.

Servers

Incoming Mails

These servers are responsible for incoming mails to @serv301.de addresses.

Hostname / IP address Priority STARTTLS Certificates Protocol
mail.cs309.de
195.201.134.54
 10
supported
mail.cs309.de
DANE
missing
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
1 s

Outgoing Mails

We have not received any emails from a @serv301.de address so far. Test mail delivery

Certificates

First seen at:

CN=mail.cs309.de

Certificate chain
  • mail.cs309.de
    • remaining
    • 4096 bit
    • sha256WithRSAEncryption
      • R13
        • remaining
        • 2048 bit
        • sha256WithRSAEncryption
          • ISRG Root X1 (Certificate is self-signed.)
            • remaining
            • 4096 bit
            • sha256WithRSAEncryption
Subject
Common Name (CN)
  • mail.cs309.de
Alternative Names
  • allstats.cs309.de
  • cp.cs309.de
  • cs309.de
  • dateimanager.cs309.de
  • imap.cs309.de
  • mail.cs309.de
  • mysql.cs309.de
  • stats.cs309.de
  • webmail.cs309.de
  • www.cs309.de
Issuer
Country (C)
  • US
Organization (O)
  • Let's Encrypt
Common Name (CN)
  • R13
validity period
Not valid before
2026-05-06
Not valid after
2026-08-04
This certifcate has been verified for the following usages:
  • Digital Signature
  • Key Encipherment
  • TLS Web Server Authentication
Fingerprints
SHA256
38:D6:2F:46:FD:99:B4:8C:0F:4D:DC:8F:05:2F:92:F0:92:C6:F1:C6:C6:95:1A:10:FD:4D:B4:9C:45:3C:68:CF
SHA1
A8:6B:1B:69:E4:05:3A:68:51:0B:BE:A8:A3:B9:2E:86:95:BA:9F:95
X509v3 extensions
subjectKeyIdentifier
  • B5:DC:53:DF:54:91:E7:52:AC:6C:1E:96:E3:4D:64:2B:EA:4C:06:91
authorityKeyIdentifier
  • keyid:E7:AB:9F:0F:2C:33:A0:53:D3:5E:4F:78:C8:B2:84:0E:3B:D6:92:33
authorityInfoAccess
  • CA Issuers - URI:http://r13.i.lencr.org/
certificatePolicies
  • Policy: 2.23.140.1.2.1
crlDistributionPoints
  • Full Name:
  • URI:http://r13.c.lencr.org/71.crl
ct_precert_scts
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : D7:6D:7D:10:D1:A7:F5:77:C2:C7:E9:5F:D7:00:BF:F9:
  • 82:C9:33:5A:65:E1:D0:B3:01:73:17:C0:C8:C5:69:77
  • Timestamp : May 6 01:50:10.670 2026 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:45:02:20:6C:12:CC:4B:AD:F6:59:29:A6:B4:6D:08:
  • 21:CC:8A:86:B0:70:11:32:97:54:78:F4:8E:AB:06:E0:
  • 75:3B:A5:2B:02:21:00:A9:22:7B:A7:16:26:E1:65:BC:
  • AC:3D:EB:23:59:EE:BA:6A:D7:47:EF:FD:13:D1:E4:39:
  • 36:8D:76:4C:8C:05:61
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : 26:E3:64:6E:58:69:21:23:BC:34:3F:47:24:35:9B:37:
  • 92:CD:24:5A:88:D8:15:D3:93:33:FD:99:18:AB:47:23
  • Timestamp : May 6 01:50:10.667 2026 GMT
  • Extensions: 00:00:05:00:0D:C0:43:62
  • Signature : ecdsa-with-SHA256
  • 30:45:02:20:1D:4D:F2:1D:A7:86:B0:32:B1:62:D1:EC:
  • C8:D4:12:60:CC:57:FD:38:F2:87:DB:11:C2:A1:73:E6:
  • 07:1E:8F:57:02:21:00:93:91:D9:F9:89:39:37:6D:64:
  • 6F:23:F0:5B:54:90:D2:68:36:A7:B9:24:EA:9A:FE:FF:
  • 0E:08:9B:DF:B2:5F:71