SSL/TLS Certificate Lookup

Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted

posteo.gr

SSL/TLS Certificate

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SSL/TLS Certificate for posteo.gr

Hostname mismatch

Issued by (CA): DigiCert Inc
Subject: posteo.de
Valid from: Feb 18, 2026
Valid until: Feb 24, 2027 (219 days remaining)
Public key: RSA 3072-bit
Serial: 0C57EE5D71289AD1D02D6675CA54C209
SHA-256 fingerprint: 67:6F:C4:53:CB:39:04:7C:37:1C:AB:C1:13:79:AA:24:20:33:E3:C6:BD:A5:36:8C:E2:73:74:FE:DF:E4:6E:2F
Chain: GeoTrust EV RSA CA G2 → DigiCert Global Root G2

Subject Alternative Names (7)

api.posteo.de, autoconfig.posteo.de, cdn.posteo.de, lists.posteo.de, mta-sts.posteo.de, posteo.de, www.posteo.de

Certificate Authority Authorization (CAA)

The serving CA (DigiCert Inc) is not among the authorities this domain's CAA records authorize (certum.pl, d-trust.net, geotrust.com). This can indicate a misconfiguration or an unexpected issuance.