DNS
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

submail.cn · 121.196.21.208:443

Unverified
Certificate verification failed. These are unverified certificate details presented by the server. Peer certificate subjectAltName did not match expected name `submail.cn'

Certificate verification failed

Subject
C=CN ST=上海市 O=上海赛邮云计算有限公司 CN=*.mysubmail.com
Issuer
C=US O=DigiCert, Inc. CN=GeoTrust G2 TLS CN RSA4096 SHA256 2022 CA1
Valid from
2026-02-24T00:00:00+00:00
Expires
2027-03-25T23:59:59+00:00
Days remaining
161
Serial (hex)
0345791432CEF22C2FDF320700425C9C
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

DNS:*.mysubmail.com, DNS:mysubmail.com

SHA-256 fingerprint

80:98:86:4F:36:DF:75:2E:C2:95:4D:A3:CC:0B:06:5B:8B:80:06:4B:54:99:C8:F1:21:1C:DD:28:C9:03:90:F9
Certificate extensions & PEM
authorityKeyIdentifier
41:4E:8E:69:9D:F4:6E:25:EC:78:14:1C:7E:D7:CD:1D:99:CF:F9:6B
subjectKeyIdentifier
C3:00:AE:20:7C:24:D8:DE:7E:E1:67:80:43:D5:EB:AE:1C:4C:18:A0
subjectAltName
DNS:*.mysubmail.com, DNS:mysubmail.com
certificatePolicies
Policy: 2.23.140.1.2.2 CPS: http://www.digicert.com/CPS
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
crlDistributionPoints
Full Name: URI:http://crl.digicert.cn/GeoTrustG2TLSCNRSA4096SHA2562022CA1.crl
authorityInfoAccess
OCSP - URI:http://ocsp.digicert.cn CA Issuers - URI:http://cacerts.digicert.cn/GeoTrustG2TLSCNRSA4096SHA2562022CA1.crt
basicConstraints
CA:FALSE
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 4C:63:DC:98:E5:9C:1D:AB:88:F6:1E:8A:3D:DE:AE:8F: AB:44:A3:37:7B:5F:9B:94:C3:FB:A1:9C:FC:C1:BE:26 Timestamp : Feb 24 05:35:38.127 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:44:02:20:77:63:D1:ED:5B:8B:57:75:0A:92:F8:A4: 96:44:10:2A:97:45:A8:AB:E6:27:E4:12:29:66:A4:A4: 67:F8:A6:80:02:20:32:01:4D:C2:67:E2:DE:C1:91:05: 86:34:5E:41:84:0E:11:FD:87:18:04:1B:70:CE:E0:36: 15:92:94:A0:A9:93 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 44:C2:BD:0C:E9:14:0E:64:A5:C9:4A:01:93:0A:5A:A1: BB:35:97:0E:00:EE:11:16:89:68:2A:1C:44:D7:B5:66 Timestamp : Feb 24 05:35:38.166 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:45:DB:C9:13:88:B6:FC:10:D5:58:1D:CE: 9A:61:C8:85:4B:99:D2:9B:58:93:D6:B3:B2:02:41:DA: D5:98:D0:40:02:21:00:CD:97:67:D7:84:C4:B3:6F:0D: 3C:DB:EB:C0:76:94:2A:F6:2E:0E:86:42:30:F5:63:67: 61:B6:38:B5:9A:7A:3A Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1C:9F:68:2C:E9:FA:F0:45:69:50:F8:1B:96:8A:87:DD: DB:32:10:D8:4C:E6:C8:B2:E3:82:52:4A:C4:CF:59:9F Timestamp : Feb 24 05:35:38.349 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:D7:77:ED:EE:DB:C8:03:AD:AB:F2:7A: 67:B9:09:74:BA:FF:39:56:F0:8F:E4:C3:46:FA:66:38: 4E:A3:CB:43:E2:02:21:00:86:6D:E4:C7:8F:90:84:DE: 52:B5:CF:6C:DF:50:C0:92:CC:4F:FE:EC:63:32:32:B4: 3D:1D:55:5A:E4:89:9B:26
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: ECDHE-RSA-AES128-GCM-SHA256 · Checked 2026-10-15T07:05:07+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=DigiCert, Inc. CN=GeoTrust G2 TLS CN RSA4096 SHA256 2022 CA1
Issuer
C=US O=DigiCert Inc OU=www.digicert.com CN=DigiCert Global Root G2
Valid from
2022-12-15T00:00:00+00:00
Expires
2032-12-14T23:59:59+00:00
Days remaining
2252
Serial (hex)
0F06BB09306148267FCA1B71C1DB807D
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

05:DC:9E:DC:0F:DD:FA:97:5A:14:32:EF:80:6E:C7:80:07:8B:53:62:AD:45:AF:76:DB:15:C9:07:63:0D:B2:5D
Certificate extensions & PEM
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
41:4E:8E:69:9D:F4:6E:25:EC:78:14:1C:7E:D7:CD:1D:99:CF:F9:6B
authorityKeyIdentifier
4E:22:54:20:18:95:E6:E3:6E:E6:0F:FA:FA:B9:12:ED:06:17:8F:39
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
authorityInfoAccess
OCSP - URI:http://ocsp.digicert.cn CA Issuers - URI:http://cacerts.digicert.cn/DigiCertGlobalRootG2.crt
crlDistributionPoints
Full Name: URI:http://crl.digicert.cn/DigiCertGlobalRootG2.crl
certificatePolicies
Policy: 2.16.840.1.114412.2.1 Policy: 2.23.140.1.1 Policy: 2.23.140.1.2.1 Policy: 2.23.140.1.2.2 Policy: 2.23.140.1.2.3
-----BEGIN CERTIFICATE-----
MIIFxjCCBK6gAwIBAgIQDwa7CTBhSCZ/yhtxwduAfTANBgkqhkiG9w0BAQsFADBh
MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3
d3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBH
MjAeFw0yMjEyMTUwMDAwMDBaFw0zMjEyMTQyMzU5NTlaMFsxCzAJBgNVBAYTAlVT
MRcwFQYDVQQKEw5EaWdpQ2VydCwgSW5jLjEzMDEGA1UEAxMqR2VvVHJ1c3QgRzIg
VExTIENOIFJTQTQwOTYgU0hBMjU2IDIwMjIgQ0ExMIICIjANBgkqhkiG9w0BAQEF
AAOCAg8AMIICCgKCAgEAn1dxOo4OzYa4O1EJd0nhFI5QB/kXAJTHRI6C1J2Gz86B
Ge9+DD8R4vexG7/QnUvV+5887o+G4enlkDwJV1Pehq4i0n+X6VKIPg5cThCx6/o0
3bUkLWld7slhi3Hli/MaosZZuytdU1uCzQlGpaLB2TiTZbDImiVaykdfwl8V6AXP
0Ab4wIcvPggl4qlwyPsBY6NODbP884BmL1ntdXfzecGst30FnAtm4w+PTo0I1T3F
ITYXaNuIJnKonD1xXaN4Ar/rvcpKpntxVyZQ2T1Lb7vlfYISqNF+1ugpTzKnI1z7
xV7tSqXd2vs6Csy6yFN+QLWwMnGWuQkvrO1m+F7V85S9ECpbqn9qNtKl8gIQ7JeZ
BmBdLroW+4j1PDzBWmSWKB+gvRubVSTuoDR3VCtlI4G/Uh+ObF4UStbhKjr1SNCW
JcrB1oF+wWBl8Bvozm4xflyyGDY47KCP/Fn9X5GHDNLQA9R0zqDKRumipp1UXswF
uzH0I+gOuqSdZSsYID9XSVq6adcJ3rIMAcTuODcrPrJssOFKGFUbmY/VxbxMgYHI
/07Zfdxoa+q0osWpofbMhLPZz9UuJFBCLsjgSckkSU02/4itmLm9e3lt6E/4q9Mc
MCaS8+qrLWKG9wQtviC8zGynEXpxjEQE8WyrfeYKyXwZFCPB4rpTw1joJmGFeLUC
AwEAAaOCAX4wggF6MBIGA1UdEwEB/wQIMAYBAf8CAQAwHQYDVR0OBBYEFEFOjmmd
9G4l7HgUHH7XzR2Zz/lrMB8GA1UdIwQYMBaAFE4iVCAYlebjbuYP+vq5Eu0GF485
MA4GA1UdDwEB/wQEAwIBhjAdBgNVHSUEFjAUBggrBgEFBQcDAQYIKwYBBQUHAwIw
dAYIKwYBBQUHAQEEaDBmMCMGCCsGAQUFBzABhhdodHRwOi8vb2NzcC5kaWdpY2Vy
dC5jbjA/BggrBgEFBQcwAoYzaHR0cDovL2NhY2VydHMuZGlnaWNlcnQuY24vRGln
aUNlcnRHbG9iYWxSb290RzIuY3J0MEAGA1UdHwQ5MDcwNaAzoDGGL2h0dHA6Ly9j
cmwuZGlnaWNlcnQuY24vRGlnaUNlcnRHbG9iYWxSb290RzIuY3JsMD0GA1UdIAQ2
MDQwCwYJYIZIAYb9bAIBMAcGBWeBDAEBMAgGBmeBDAECATAIBgZngQwBAgIwCAYG
Z4EMAQIDMA0GCSqGSIb3DQEBCwUAA4IBAQAkpDVI+nCKnAEEpDfldytHXUYOr2ys
aGeboE3d1KAN4Gt+eioRvgNdmDKbVFCYY0C6ErIXIvSGXafsprU2dclka/kmH+9U
4q3v5Acx6KwcnEuYLN0QOtrlQ9s3Z4IbIzdYUv8IauXC27a3x99x2WMVxNu1KGJy
0r1Z+Xya1adf9/e1LFj1CGdq9HfQ/HFWP2khzxQZ4u62sOHuZdPgtNidFOhQLC+2
5cNsPgqsaCrGLbSjzni7VN7NhAbTsLhA1oz41vHHB+q4ZzNlC01elmPBOtupe2HM
/lqMA/J/nTxc718THdxpszFllAET1/lFEolnqihpUFPaPjRwU7yZIseS
-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=DigiCert Inc OU=www.digicert.com CN=DigiCert Global Root G2
Issuer
C=US O=DigiCert Inc OU=www.digicert.com CN=DigiCert Global Root CA
Valid from
2024-01-18T00:00:00+00:00
Expires
2031-11-09T23:59:59+00:00
Days remaining
1851
Serial (hex)
0FE032AB844D033106C50C8E13C8B068
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

79:D5:7B:15:DF:A6:5C:28:70:EA:FE:11:B6:37:76:59:09:CF:E9:37:B4:9C:15:CE:7F:19:40:30:CA:B3:95:AD
Certificate extensions & PEM
basicConstraints
CA:TRUE
subjectKeyIdentifier
4E:22:54:20:18:95:E6:E3:6E:E6:0F:FA:FA:B9:12:ED:06:17:8F:39
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
authorityInfoAccess
OCSP - URI:http://ocsp.digicert.cn CA Issuers - URI:http://cacerts.digicert.cn/DigiCertGlobalRootCA.crt
crlDistributionPoints
Full Name: URI:http://crl.digicert.cn/DigiCertGlobalRootCA.crl
certificatePolicies
Policy: X509v3 Any Policy
-----BEGIN CERTIFICATE-----
MIIEfjCCA2agAwIBAgIQD+Ayq4RNAzEGxQyOE8iwaDANBgkqhkiG9w0BAQsFADBh
MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3
d3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBD
QTAeFw0yNDAxMTgwMDAwMDBaFw0zMTExMDkyMzU5NTlaMGExCzAJBgNVBAYTAlVT
MRUwEwYDVQQKEwxEaWdpQ2VydCBJbmMxGTAXBgNVBAsTEHd3dy5kaWdpY2VydC5j
b20xIDAeBgNVBAMTF0RpZ2lDZXJ0IEdsb2JhbCBSb290IEcyMIIBIjANBgkqhkiG
9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuzfNNNx7a8myaJCtSnX/RrohCgiN9RlUyfuI
2/Ou8jqJkTx65qsGGmvPrC3oXgkkRLpimn7Wo6h+4FR1IAWsULecYxpsMNzaHxmx
1x7e/dfgy5SDN67sH0NO3Xss0r0upS/kqbitOtSZpLYl6ZtrAGCSYP9PIUkY92eQ
q2EGnI/yuum06ZIya7XzV+hdG82MHauVBJVJ8zUtluNJbd134/tJS7SsVQepj5Wz
tCO7TG1F8PapspUwtP1MVYwnSlcUfIKdzXOS0xZKBgyMUNGPHgm+F6HmIcr9g+UQ
vIOlCsRnKPZzFBQ9RnbDhxSJITRNrw9FDKZJobq7nMWxM4MphQIDAQABo4IBMDCC
ASwwDwYDVR0TAQH/BAUwAwEB/zAdBgNVHQ4EFgQUTiJUIBiV5uNu5g/6+rkS7QYX
jzkwHwYDVR0jBBgwFoAUA95QNVbRTLtm8KPiGxvDl7I90VUwDgYDVR0PAQH/BAQD
AgGGMHQGCCsGAQUFBwEBBGgwZjAjBggrBgEFBQcwAYYXaHR0cDovL29jc3AuZGln
aWNlcnQuY24wPwYIKwYBBQUHMAKGM2h0dHA6Ly9jYWNlcnRzLmRpZ2ljZXJ0LmNu
L0RpZ2lDZXJ0R2xvYmFsUm9vdENBLmNydDBABgNVHR8EOTA3MDWgM6Axhi9odHRw
Oi8vY3JsLmRpZ2ljZXJ0LmNuL0RpZ2lDZXJ0R2xvYmFsUm9vdENBLmNybDARBgNV
HSAECjAIMAYGBFUdIAAwDQYJKoZIhvcNAQELBQADggEBAHRBl3jN7+XHBUK0dZnu
hMdoNwD1nCROU3BTIh1TNzRI0bQ0m5+C/dCRzzlqoSAFHUlOi+OiDltWkXTzmQn6
Z8bH5PFBy5sYpc/8cNPoSzhyqcpvvEZvv/Ivc0Up+dzma7vBDJC9WrMRUUlSFSQp
kdXSmphDNkXJsgARmxzc18IN6LYMRiOWlY7RE2F900pPW60BvJHHNCX0bbSRj/Ql
bmVq8wuftBD++D+RS8K++ujpMjFBROyWfBX+woQDGsMazkmgulQdnZrdj476elOL
axRvrSgEorju1kJM7M65z2RUZrfzQYW/1rs8mRUXin6iEtad/Rv1ZI1WGYmWPyBm
pbo=
-----END CERTIFICATE-----

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

View certificate JSON

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