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

TLSv1.3

mailcow.madgenius.com · 107.175.232.100:443

Verified

Certificate chain, hostname and dates verified using this server’s CA store.

Subject
CN=mailcow.madgenius.com
Issuer
C=US O=Let's Encrypt CN=YR2
Valid from
2026-09-24T12:37:46+00:00
Expires
2026-12-23T12:37:45+00:00
Days remaining
46
Serial (hex)
06221A2037559D188BDAFEB6F6898809A693
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:autoconfig.madgenius.com, DNS:autodiscover.madgenius.com, DNS:mailcow.madgenius.com

SHA-256 fingerprint

72:4C:F3:52:F3:86:32:D8:28:E8:A2:2C:47:D4:7E:45:FD:98:59:19:F1:E4:32:78:DF:7E:AC:F0:B5:3D:A7:34
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
78:FB:B0:EB:BA:4A:D8:29:1E:2A:99:AF:7F:BC:3F:60:36:AB:14:07
authorityKeyIdentifier
40:15:2D:26:79:ED:32:20:9E:DF:9A:72:1D:D6:32:1F:81:0C:81:0C
authorityInfoAccess
CA Issuers - URI:http://yr2.i.lencr.org/
subjectAltName
DNS:autoconfig.madgenius.com, DNS:autodiscover.madgenius.com, DNS:mailcow.madgenius.com
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr2.c.lencr.org/20.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : CB:38:F7:15:89:7C:84:A1:44:5F:5B:C1:DD:FB:C9:6E: F2:9A:59:CD:47:0A:69:05:85:B0:CB:14:C3:14:58:E7 Timestamp : Sep 24 13:36:16.196 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:46:02:21:00:D9:1C:12:B2:6B:19:A2:32:36:BA:06: 2E:B7:36:B6:8D:86:8E:29:3A:BD:4A:A2:F6:9E:52:72: 7A:52:CE:86:AB:02:21:00:94:5C:35:C3:B2:A1:FF:B2: 43:1F:6F:36:D5:D2:1E:BA:07:70:CF:3D:BD:6A:19:04: 5E:9B:8A:32:F5:23:31:6D Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 1A:8B:9D:6B:0F:FE:BF:81:B4:79:39:C6:D2:31:0A:86: D6:D1:02:D4:F0:46:E2:18:2C:9D:E3:5F:5E:26:25:EF Timestamp : Sep 24 13:36:17.504 2026 GMT Extensions: 00:00:05:00:44:B1:F7:7D Signature : ecdsa-with-SHA256 30:44:02:20:67:18:7E:69:C3:6A:01:80:4C:78:11:A7: 39:62:5C:D0:0C:60:D1:EA:E7:7A:E0:9C:BE:4F:1D:CD: 9B:97:D2:3A:02:20:73:FE:F1:92:DF:15:7A:0D:3F:4C: C2:7F:73:8F:E0:F4:7F:44:A9:5B:8C:28:B7:98:78:8E: F7:1F:BA:7B:9D:56
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-11-06T19:49:16+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YR2
Issuer
C=US O=ISRG CN=Root YR
Valid from
2025-09-03T00:00:00+00:00
Expires
2028-09-02T23:59:59+00:00
Days remaining
666
Serial (hex)
4EBD24947E24D394802D84A52FD5B319
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

23:8B:85:A0:09:9C:65:B9:70:47:7D:57:24:F1:A1:D4:75:CE:50:58:CF:FE:4E:FA:87:33:89:9B:DB:86:3C:47
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
40:15:2D:26:79:ED:32:20:9E:DF:9A:72:1D:D6:32:1F:81:0C:81:0C
authorityKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityInfoAccess
CA Issuers - URI:http://yr.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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==
-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=ISRG CN=Root YR
Issuer
C=US O=Internet Security Research Group CN=ISRG Root X1
Valid from
2026-05-13T00:00:00+00:00
Expires
2032-09-02T23:59:59+00:00
Days remaining
2127
Serial (hex)
F24B6D17F9D9AD7CB1C9FEA78782699F
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

07:26:39:D0:B1:40:D5:BF:FA:E1:6A:D9:C3:F6:CC:60:86:04:06:21:F5:1E:E6:1A:6D:46:A8:91:5C:07:CF:76
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
DE:E7:5B:60:D0:22:6D:40:28:7D:3F:0D:01:FE:A4:B5:52:B4:51:94
authorityKeyIdentifier
79:B4:59:E6:7B:B6:E5:E4:01:73:80:08:88:C8:1A:58:F6:E9:9B:6E
authorityInfoAccess
CA Issuers - URI:http://x1.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://x1.c.lencr.org/ 
-----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.

View certificate JSON

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