SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
12-mail.cz
SSL/TLS Certificate
SSL/TLS Certificate for 12-mail.cz
Hostname mismatch- Issued by (CA)
- Let's Encrypt
- Subject
- webbase.12-web.cz
- Valid from
- Jul 2, 2026
- Valid until
- Sep 30, 2026 (15 days remaining)
- Public key
- RSA 4096-bit
- Serial
- 056BFFB6E59F83D0F0B36E4A6FE93627CE10
- SHA-256 fingerprint
- 29:DD:3A:3E:3E:86:7E:CC:7A:A5:81:41:AE:D6:6B:E3:EB:99:E8:6E:93:89:62:88:B0:D7:46:2A:A6:98:0B:4B
- Chain
- YR2 → Root YR → ISRG Root X1
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
This certificate has been served since Aug 15, 2026.
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Uptime
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DNS changes
We watch NS, MX, CAA, DNSSEC, CNAME and A/AAAA records, and identify the host, network, and ASN behind them, so a real migration or hijack stands out from routine noise.
TLS certificate
We warn you 30, 14, 7, and 1 days before it expires, and flag it if the issuing authority changes or the certificate is unexpectedly replaced.
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