SSL-Tools

SSL check results of catfish.optonet.com.pl

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Discover if the mail servers for catfish.optonet.com.pl 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, 05 Oct 2026 11:03:02 +0000

The mailservers of catfish.optonet.com.pl can be reached through a secure connection.

Servers

Incoming Mails

These servers are responsible for incoming mails to @catfish.optonet.com.pl addresses.

Hostname / IP address Priority STARTTLS Certificates Protocol
catfish.optonet.com.pl
88.220.84.180
 -
supported
catfish.optonet.com.pl
DANE
missing
PFS
supported
Heartbleed
not vulnerable
Weak ciphers
not found
  • TLSv1.2
  • SSLv3
12 s

Outgoing Mails

We have not received any emails from a @catfish.optonet.com.pl address so far. Test mail delivery

Certificates

First seen at:

CN=catfish.optonet.com.pl

Certificate chain
  • catfish.optonet.com.pl
    • remaining
    • 256 bit
    • ecdsa-with-SHA384
      • YE1
        • remaining
        • 384 bit
        • ecdsa-with-SHA384
          • Root YE
            • remaining
            • 384 bit
            • ecdsa-with-SHA384
              • ISRG Root X2 (Certificate is self-signed.)
                • remaining
                • 384 bit
                • ecdsa-with-SHA384
Subject
Common Name (CN)
  • catfish.optonet.com.pl
Alternative Names
  • catfish.optonet.com.pl
Issuer
Country (C)
  • US
Organization (O)
  • Let's Encrypt
Common Name (CN)
  • YE1
validity period
Not valid before
2026-09-01
Not valid after
2026-11-30
This certifcate has been verified for the following usages:
  • Digital Signature
  • TLS Web Server Authentication
Fingerprints
SHA256
D3:5B:89:D7:01:DA:37:C3:57:30:75:2E:FA:AF:85:DE:8C:1F:EA:E8:B1:60:B1:40:92:E7:61:DA:08:8D:FC:94
SHA1
76:5F:AE:69:EC:1B:45:D8:8F:68:1A:B6:7B:C4:74:47:03:12:78:8D
X509v3 extensions
subjectKeyIdentifier
  • FC:DC:0E:92:F5:49:E4:2D:73:9F:F0:01:E5:A9:51:A7:F2:3C:1E:20
authorityKeyIdentifier
  • keyid:BB:20:CA:47:0B:FE:D7:E5:9C:F9:8F:09:2A:A3:8C:37:45:B1:BC:D8
authorityInfoAccess
  • CA Issuers - URI:http://ye1.i.lencr.org/
certificatePolicies
  • Policy: 2.23.140.1.2.1
crlDistributionPoints
  • Full Name:
  • URI:http://ye1.c.lencr.org/121.crl
ct_precert_scts
  • Signed Certificate Timestamp:
  • Version : v1 (0x0)
  • Log ID : CB:38:F7:15:89:7C:84:A1:44:5F:5B:C1:DD:FB:C9:6E:
  • F2:9A:59:CD:47:0A:69:05:85:B0:CB:14:C3:14:58:E7
  • Timestamp : Sep 1 12:52:13.435 2026 GMT
  • Extensions: none
  • Signature : ecdsa-with-SHA256
  • 30:45:02:20:42:AB:8D:40:CC:8A:44:77:5F:0A:51:9E:
  • A6:F1:14:67:27:97:68:AF:2D:D8:E9:1F:40:FE:51:E8:
  • E3:7B:27:DC:02:21:00:C8:CE:46:37:32:68:CE:B4:A6:
  • 6F:36:28:3A:B9:87:33:DF:F7:B2:3B:68:9C:1C:01:5D:
  • 8A:55:B9:00:F5:84:F8
  • 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 : Sep 1 12:52:11.949 2026 GMT
  • Extensions: 00:00:05:00:3B:9E:DE:1F
  • Signature : ecdsa-with-SHA256
  • 30:44:02:20:28:CE:CE:F3:2F:D5:5C:1C:44:63:2C:4E:
  • E6:F5:14:1E:D7:53:0F:49:2A:FF:05:07:C4:24:E9:39:
  • 26:74:F2:3D:02:20:5D:9E:7F:4D:84:A0:48:E8:FE:13:
  • 13:3A:54:69:53:1B:D5:2E:08:F1:65:55:F5:78:E3:8E:
  • 6C:2A:67:C2:6C:A2