SSL certificate checker
Check when the SSL/TLS certificate of a website or mail server expires - including SMTP, IMAP and POP3 with STARTTLS. Free, no sign-up.
The same check in a terminal
echo | openssl s_client -connect example.com:443 -servername example.com 2>/dev/null | openssl x509 -noout -dates -subject -issuerHow do I check when my mail server certificate expires?
Enter the mail server name (for example mail.example.com), choose “Mail - SMTP STARTTLS (587)” or “IMAP SSL (993)” and click Check. You get the expiry date, days left, issuer and the names the certificate is valid for.
What does “certificate does not match this name” mean?
The certificate was issued for other names than the one you checked. Browsers and mail clients will show a warning. The certificate needs to include that name (or a matching *.domain wildcard).
Why is the chain not trusted?
The certificate is expired, self-signed, or the server does not send the intermediate certificate. The error code next to the result tells which one.
Can I check servers on my local network?
No. For security the tool only connects to public addresses and standard ports (443, 8443, 25, 587, 465, 143, 993, 110, 995).