SSL/TLS Certificate Lookup

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

posteo.at

SSL/TLS Certificate

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SSL/TLS Certificate for posteo.at

Valid
Issued by (CA)
DigiCert Inc
Subject
posteo.net
Valid from
Jun 15, 2026
Valid until
Dec 30, 2026 (156 days remaining)
Public key
RSA 3072-bit
Serial
095E7BE63C491EF66C7B1070671A438C
SHA-256 fingerprint
DE:1D:68:A2:E5:D9:90:65:8A:6B:B3:B2:B2:A5:D9:D1:9A:6D:0A:9E:BA:42:CA:C0:47:76:B2:0B:AA:D9:4F:6A
Chain
GeoTrust EV RSA CA G2 → DigiCert Global Root G2
Subject Alternative Names (45)
mta-sts.posteo.at, mta-sts.posteo.au, mta-sts.posteo.be, mta-sts.posteo.ca, mta-sts.posteo.ch, mta-sts.posteo.es, mta-sts.posteo.eu, mta-sts.posteo.ie, mta-sts.posteo.lu, mta-sts.posteo.mx, mta-sts.posteo.net, mta-sts.posteo.nl, mta-sts.posteo.nz, mta-sts.posteo.uk, mta-sts.posteo.us, posteo.at, posteo.au, posteo.be, posteo.ca, posteo.ch, posteo.es, posteo.eu, posteo.ie, posteo.lu, posteo.mx, posteo.net, posteo.nl, posteo.nz, posteo.uk, posteo.us, www.posteo.at, www.posteo.au, www.posteo.be, www.posteo.ca, www.posteo.ch, www.posteo.es, www.posteo.eu, www.posteo.ie, www.posteo.lu, www.posteo.mx, www.posteo.net, www.posteo.nl, www.posteo.nz, www.posteo.uk, www.posteo.us

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.

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TLS certificate

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