Verschlüsselte Verbindungen, ob imap, smtp, pop oder web sind nur solange sicher, wie verifiziert werden kann, dass sich der mit einem Zertifikat meldende Server tatsächlich unseren Erwartungen entspricht und nicht etwa ein ‘man-in-the-middle’ die vermeintlich verschluesselte Verbindung belauscht. Zu diesem Zweck gibt es nachfolgend eine Auflistung der von uns auf unseren Servern eingesetzten Zertifikate- und deren Fingerprints:

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[
  {
    "subject_CN": "rage.so36.net",
    "subjectAltName": "DNS:imap.so36.net, DNS:mail.so36.net, DNS:pop.so36.net, DNS:pop3.so36.net, DNS:rage.so36.net, DNS:smtp.so36.net",
    "serial": "03A3A53F6F29E08EB6E739C928CC6EC29709",
    "fingerprint_sha1": "18b0a97b73cd613e02075baf431cf053cb28be91",
    "fingerprint_sha256": "02e7f4f22497b7d7e5bc1b55869b0efcfd3e38f505034acb6b6116166b5b4004",
    "not_before": "2018-05-30 00:59:29 UTC",
    "not_after": "2018-08-28 00:59:29 UTC",
    "issuer_CN": "Let's Encrypt Authority X3"
  },
  {
    "subject_CN": "webmail.so36.net",
    "subjectAltName": "DNS:webmail.so36.net",
    "serial": "03CF56C1CA23A86976BAC71D77740A3FD961",
    "fingerprint_sha1": "372ab7652f5c673efeadaac26f0c1a46b87d8b96",
    "fingerprint_sha256": "b8b839ed1fa365dd67b425f3f0a45a8a7de20b059db6a3c320f08030179690b5",
    "not_before": "2018-05-29 00:59:16 UTC",
    "not_after": "2018-08-27 00:59:16 UTC",
    "issuer_CN": "Let's Encrypt Authority X3"
  },
  {
    "subject_CN": "www.so36.net",
    "subjectAltName": "DNS:so36.net, DNS:www.so36.net",
    "serial": "0376F139B89440D0E65DC9605E03F69C2E93",
    "fingerprint_sha1": "88fccfa5806b9feb50abc1fd82911dcf244afba8",
    "fingerprint_sha256": "a9dbfd2610264623a01ee08eeb7f0abfdc26e1e2691d82a10a34f00edf29fd4c",
    "not_before": "2018-05-25 02:23:38 UTC",
    "not_after": "2018-08-23 02:23:38 UTC",
    "issuer_CN": "Let's Encrypt Authority X3"
  },
  {
    "subject_CN": "codecoop.org",
    "subjectAltName": "DNS:codecoop.org, DNS:git.codecoop.org",
    "serial": "03DB034513F8D6DF1CAA8F4E9A438B0A0B86",
    "fingerprint_sha1": "90859e8581a3cc4f09fec027603b2b8cc1c19557",
    "fingerprint_sha256": "285fa3e46f62da6ec9966dd92574e8f8716c2e3b45084f7c52881680b90ef83c",
    "not_before": "2018-06-15 02:28:15 UTC",
    "not_after": "2018-09-13 02:28:15 UTC",
    "issuer_CN": "Let's Encrypt Authority X3"
  },
  {
    "subject_CN": "jabber.so36.net",
    "subjectAltName": "DNS:jabber.so36.net",
    "serial": "030DE97EBD6CE409F107633F919118C47305",
    "fingerprint_sha1": "11d65eb776155e27e4278f049f88bd503258bb1e",
    "fingerprint_sha256": "d194c6e2e8e5c47bb7e725eeaba815105afa01b88de4bb2b4798433a8f43fc99",
    "not_before": "2018-06-16 22:21:07 UTC",
    "not_after": "2018-09-14 22:21:07 UTC",
    "issuer_CN": "Let's Encrypt Authority X3"
  },
  {
    "subject_CN": "talk36.net",
    "subjectAltName": "DNS:talk36.net",
    "serial": "03BD5D2F7439B6C46F607869F2B6B0DB5FC6",
    "fingerprint_sha1": "9fe2e994cd31953be33bddad2082584232639b25",
    "fingerprint_sha256": "23001cbb35afbea9088eca33ad77722d8c4d52bd59ab6e509879235ccdd95e2f",
    "not_before": "2018-06-09 22:21:07 UTC",
    "not_after": "2018-09-07 22:21:07 UTC",
    "issuer_CN": "Let's Encrypt Authority X3"
  },
  {
    "subject_CN": "lists36.net",
    "subjectAltName": "DNS:lists36.net",
    "serial": "033666A55C4FD2AD37E1190DAEF0973E9B83",
    "fingerprint_sha1": "d58385d0569417818ff6fcc8a449063f8b49870f",
    "fingerprint_sha256": "c01863cd4b36b5eb9e2249f7edc61be502ca40f82719a77b0fc95ef7a00a8dcb",
    "not_before": "2018-06-21 02:21:08 UTC",
    "not_after": "2018-09-19 02:21:08 UTC",
    "issuer_CN": "Let's Encrypt Authority X3"
  }
]
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