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THE CERTIFICATE BEHIND THE CONNECTION

TLS certificate checker.

Inspect SSL/TLS certificates for any public domain or subdomain.

Checks HTTPS on port 443, including subject alternative names, validity dates and the presented chain.

SSL certificate

TLSv1.2

mainmail.net · 138.121.98.155:443

Unverified
Certificate verification failed. These are unverified certificate details presented by the server. SSL operation failed with code 1. OpenSSL Error messages: error:0A000086:SSL routines::certificate verify failed
The certificate has expired.

Certificate verification failed

Subject
CN=mail.mainmail.net
Issuer
C=US O=DigiCert Inc OU=www.digicert.com CN=GeoTrust TLS RSA CA G1
Valid from
2023-04-09T00:00:00+00:00
Expires
2024-05-09T23:59:59+00:00
Days remaining
-892
Serial (hex)
0A1B5A91F1B7776BBA541A263FF0B4C7
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:mail.mainmail.net

SHA-256 fingerprint

39:83:56:BE:DF:5F:62:E5:65:52:3B:B4:B7:09:08:4F:0F:29:AB:84:9B:35:DE:51:9A:75:AA:AF:C0:E2:92:81
Certificate extensions & PEM
authorityKeyIdentifier
94:4F:D4:5D:8B:E4:A4:E2:A6:80:FE:FD:D8:F9:00:EF:A3:BE:02:57
subjectKeyIdentifier
76:19:41:53:60:16:C4:42:8B:70:E6:C7:B1:E3:65:39:13:81:D8:95
subjectAltName
DNS:mail.mainmail.net
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
crlDistributionPoints
Full Name: URI:http://cdp.geotrust.com/GeoTrustTLSRSACAG1.crl
certificatePolicies
Policy: 2.23.140.1.2.1 CPS: http://www.digicert.com/CPS
authorityInfoAccess
OCSP - URI:http://status.geotrust.com CA Issuers - URI:http://cacerts.geotrust.com/GeoTrustTLSRSACAG1.crt
basicConstraints
CA:FALSE
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : EE:CD:D0:64:D5:DB:1A:CE:C5:5C:B7:9D:B4:CD:13:A2: 32:87:46:7C:BC:EC:DE:C3:51:48:59:46:71:1F:B5:9B Timestamp : Apr 9 14:20:20.021 2023 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:A8:66:9E:80:CE:90:97:1F:8C:31:60: A3:ED:B3:96:20:16:7F:62:E5:6C:41:E4:EE:BE:06:45: FF:FB:D9:F7:DC:02:20:7B:4E:4A:AE:71:70:61:0E:C5: 8C:76:C1:51:1C:7E:34:89:EA:9C:A6:E6:C5:2B:C5:BD: D6:CF:15:24:9C:3E:F1 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 73:D9:9E:89:1B:4C:96:78:A0:20:7D:47:9D:E6:B2:C6: 1C:D0:51:5E:71:19:2A:8C:6B:80:10:7A:C1:77:72:B5 Timestamp : Apr 9 14:20:20.056 2023 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:6E:F7:AF:29:77:23:18:38:10:25:21:49: 6C:92:45:15:42:99:9A:47:8D:10:C2:94:EB:F5:C0:3D: D1:DB:F3:72:02:20:6E:65:B3:50:34:7C:8B:90:66:B6: 05:8C:13:6F:38:01:AC:7B:43:B4:54:60:0D:4F:FF:D8: 14:C2:97:BE:18:A2 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 48:B0:E3:6B:DA:A6:47:34:0F:E5:6A:02:FA:9D:30:EB: 1C:52:01:CB:56:DD:2C:81:D9:BB:BF:AB:39:D8:84:73 Timestamp : Apr 9 14:20:20.003 2023 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:F0:93:86:ED:39:52:6C:E3:D9:57:27: B7:5C:4A:A1:A0:D3:14:85:FB:2D:DD:3C:9A:88:7B:79: 3E:48:E2:A5:72:02:21:00:CE:51:6C:10:7B:99:5C:C0: 1C:E4:26:A7:48:28:53:8C:CC:28:8E:5C:01:EA:5C:75: 3D:D8:BF:86:85:25:E0:EE
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: ECDHE-RSA-AES256-GCM-SHA384 · Checked 2026-10-18T10:37:28+00:00

Server-presented chain · 1 additional certificate

Chain certificate 1

Subject
C=US O=DigiCert Inc OU=www.digicert.com CN=GeoTrust RSA CA 2018
Issuer
C=US O=DigiCert Inc OU=www.digicert.com CN=DigiCert Global Root CA
Valid from
2017-11-06T12:23:45+00:00
Expires
2027-11-06T12:23:45+00:00
Days remaining
384
Serial (hex)
0546FE1823F7E1941DA39FCE14C46173
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

8C:C3:4E:11:C1:67:04:58:24:AD:E6:1C:49:07:A6:44:0E:DB:2C:43:98:E9:9C:11:2A:85:9D:66:1F:8E:2B:C7
Certificate extensions & PEM
subjectKeyIdentifier
90:58:FF:B0:9C:75:A8:51:54:77:B1:ED:F2:A3:43:16:38:9E:6C:C5
authorityKeyIdentifier
03:DE:50:35:56:D1:4C:BB:66:F0:A3:E2:1B:1B:C3:97:B2:3D:D1:55
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
basicConstraints
CA:TRUE, pathlen:0
authorityInfoAccess
OCSP - URI:http://ocsp.digicert.com
crlDistributionPoints
Full Name: URI:http://crl3.digicert.com/DigiCertGlobalRootCA.crl
certificatePolicies
Policy: X509v3 Any Policy CPS: https://www.digicert.com/CPS
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

One endpoint on port 443. Server-presented chain; no revocation, OCSP, CT or full TLS security scan.

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