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

mx1.high5.nl · 46.23.88.40:443

Verified

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

Subject
CN=mx1.high5.nl
Issuer
C=US O=Let's Encrypt CN=YE1
Valid from
2026-10-19T21:42:50+00:00
Expires
2027-01-17T21:42:49+00:00
Days remaining
75
Serial (hex)
05C09CF4FA7DE466D80D830BDBD609FC179A
Signature
ecdsa-with-SHA384
Public key
EC 384 secp384r1

Subject alternative names (SAN)

DNS:mta-sts.high5.nl, DNS:mta-sts.obsda.ms, DNS:mta-sts.openbsd.amsterdam, DNS:mx1.high5.nl

SHA-256 fingerprint

28:BE:61:E7:36:B1:A6:4C:BC:64:C0:59:9B:AB:BC:C6:9D:5E:2B:57:47:E1:62:A3:4F:80:26:0D:4B:D8:AE:45
Certificate extensions & PEM
keyUsage
Digital Signature
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
E1:46:64:BF:BF:60:52:E2:94:7A:99:10:A8:6C:39:2F:58:9A:25:AE
authorityKeyIdentifier
BB:20:CA:47:0B:FE:D7:E5:9C:F9:8F:09:2A:A3:8C:37:45:B1:BC:D8
authorityInfoAccess
CA Issuers - URI:http://ye1.i.lencr.org/
subjectAltName
DNS:mta-sts.high5.nl, DNS:mta-sts.obsda.ms, DNS:mta-sts.openbsd.amsterdam, DNS:mx1.high5.nl
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://ye1.c.lencr.org/27.crl
ct_precert_scts
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 : Oct 19 22:41:20.901 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:20:14:3D:BE:CA:6A:4F:80:C0:A7:1E:D5:0A: BA:6F:82:09:B1:A9:EF:1A:F8:CC:B4:A0:0D:7F:A8:2F: 4B:3B:99:21:02:21:00:E0:B3:1E:AA:F7:4F:BC:9E:33: 29:EA:4B:04:2C:61:2C:07:94:8A:3E:30:E0:E4:D9:88: 02:DC:63:84:CB:2E:8D Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 44:E8:22:FC:2B:AB:0E:92:EE:D0:E9:FA:D6:96:64:60: 27:76:D0:17:60:E0:89:05:09:C9:23:A1:B0:3F:C3:7F Timestamp : Oct 19 22:41:18.068 2026 GMT Extensions: 00:00:05:00:0C:F1:87:D9 Signature : ecdsa-with-SHA256 30:45:02:21:00:C7:8F:AD:07:0C:3D:AD:97:79:77:3F: 42:42:AA:42:F7:F4:24:14:AA:36:09:39:FB:A5:51:10: AF:B9:FF:1E:C5:02:20:6E:36:2C:1F:CB:82:7E:1F:AF: 3D:B6:0F:E2:8B:EF:71:1E:98:1D:7F:92:50:3C:6A:39: 8A:A1:6B:A7:4A:69:F7
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-11-03T04:01:32+00:00

Server-presented chain · 3 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YE1
Issuer
C=US O=ISRG CN=Root YE
Valid from
2025-09-03T00:00:00+00:00
Expires
2028-09-02T23:59:59+00:00
Days remaining
669
Serial (hex)
5DDD70DD31F801C85C186A7A04B80AFE
Signature
ecdsa-with-SHA384
Public key
EC 384 secp384r1

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

A2:37:2D:06:43:1E:97:16:36:5E:EE:D4:7E:C0:20:35:14:97:D1:82:FC:C0:38:E4:57:E5:81:68:A0:3C:AC:07
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
BB:20:CA:47:0B:FE:D7:E5:9C:F9:8F:09:2A:A3:8C:37:45:B1:BC:D8
authorityKeyIdentifier
A3:C8:26:5A:8E:A1:4C:D0:35:63:FC:9B:23:C8:3A:AE:56:F3:4F:56
authorityInfoAccess
CA Issuers - URI:http://ye.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://ye.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 2

Subject
C=US O=ISRG CN=Root YE
Issuer
C=US O=Internet Security Research Group CN=ISRG Root X2
Valid from
2026-05-13T00:00:00+00:00
Expires
2032-09-02T23:59:59+00:00
Days remaining
2130
Serial (hex)
872165FC34B6E5FBA8ADD5B3705FB53A
Signature
ecdsa-with-SHA384
Public key
EC 384 secp384r1

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

0F:C0:90:1C:CA:2B:AE:9E:9F:DB:B0:2D:50:D0:2F:10:94:F7:B3:66:72:08:69:91:B9:E8:97:62:6D:C4:85:F0
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
A3:C8:26:5A:8E:A1:4C:D0:35:63:FC:9B:23:C8:3A:AE:56:F3:4F:56
authorityKeyIdentifier
7C:42:96:AE:DE:4B:48:3B:FA:92:F8:9E:8C:CF:6D:8B:A9:72:37:95
authorityInfoAccess
CA Issuers - URI:http://x2.i.lencr.org/
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://x2.c.lencr.org/ 
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Chain certificate 3

Subject
C=US O=Internet Security Research Group CN=ISRG Root X2
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
2130
Serial (hex)
6C8F1DC727C7117F7BAF853AC980F9CD
Signature
RSA-SHA256
Public key
EC 384 secp384r1

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

EE:5F:7A:BD:69:81:BB:02:55:63:2C:D8:F4:92:83:45:1B:4B:18:84:4D:12:04:0B:44:EE:00:F0:7B:8F:E2:C6
Certificate extensions & PEM
keyUsage
Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication, TLS Web Client Authentication
basicConstraints
CA:TRUE
subjectKeyIdentifier
7C:42:96:AE:DE:4B:48:3B:FA:92:F8:9E:8C:CF:6D:8B:A9:72:37:95
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-----
MIIEcDCCAligAwIBAgIQbI8dxyfHEX97r4U6yYD5zTANBgkqhkiG9w0BAQsFADBP
MQswCQYDVQQGEwJVUzEpMCcGA1UEChMgSW50ZXJuZXQgU2VjdXJpdHkgUmVzZWFy
Y2ggR3JvdXAxFTATBgNVBAMTDElTUkcgUm9vdCBYMTAeFw0yNjA1MTMwMDAwMDBa
Fw0zMjA5MDIyMzU5NTlaME8xCzAJBgNVBAYTAlVTMSkwJwYDVQQKEyBJbnRlcm5l
dCBTZWN1cml0eSBSZXNlYXJjaCBHcm91cDEVMBMGA1UEAxMMSVNSRyBSb290IFgy
MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEzZvVn4CDCuwJSvMWSj5cz3es3mcFDR0H
ttwW+1qLFNvicWDEukWVEYmO6gbf9yoWHKS5xcUy4APgHoIYOIvXRdgKam7mAHf7
AlF9ItgKbppbd9/w+kHsOdx1ymgHDB/qo4H1MIHyMA4GA1UdDwEB/wQEAwIBBjAd
BgNVHSUEFjAUBggrBgEFBQcDAQYIKwYBBQUHAwIwDwYDVR0TAQH/BAUwAwEB/zAd
BgNVHQ4EFgQUfEKWrt5LSDv6kviejM9ti6lyN5UwHwYDVR0jBBgwFoAUebRZ5nu2
5eQBc4AIiMgaWPbpm24wMgYIKwYBBQUHAQEEJjAkMCIGCCsGAQUFBzAChhZodHRw
Oi8veDEuaS5sZW5jci5vcmcvMBMGA1UdIAQMMAowCAYGZ4EMAQIBMCcGA1UdHwQg
MB4wHKAaoBiGFmh0dHA6Ly94MS5jLmxlbmNyLm9yZy8wDQYJKoZIhvcNAQELBQAD
ggIBAD2/e9frmMxNpCV03qUHegg+MV2wz9644YoXdqtH8RyWYcBO7xfjjGEXdU1e
/o0OkEFiynUCOSIk/vLLo7ttz6CPAeNlWfC0XNkoGeWgK6jjXvozBaGuGH5n0Ufo
shMeWTuURqNN5G00sSXDTBrpp2+mgvdZQjb8K11TYMA25QA+YHNfbIEL0BniAhKS
2gsnJjSzrdZLI+EZ7SEyqdR2rkjd1KutLDU+n3TFyxjniZVGur4YlhMP3mY/dV95
IruAkkjOZier6hGBdEgZXXvaCz9u9iVEadsIE75pAGL8oHV5vxdARDiotRpul1IN
/UZwzAbrfUFcw1HkAcYD/mlZfnQ2ieCF2MS7j3Vhv7JPDKp45fmykmzYNSrumRW0
upFFKDBOoF7hsOb7oLyHS+Uft6jOUfOrogj8YUx38hKb2K20r42OgsSdDdxdeYWc
MS3Sb6mwJeSZEYxJ2gaXnDSPaKhhrNkYwljyVQyr4Nq+MEJytXNTnHqaAcrNwZlV
pcJL1KBnMrMjP7eanvUwL3FYj3cF17jtboLt7gLoi4+2rWZFvn+w54jmd/FIuhhZ
cEaU/wvU6BUNMtcVquVGHp7itQeDth5j+XL3j4WJ2SABwzUl6OeYdgpIt/ITZa+p
TT0mQ/r5XyA4MEAiabn7XJjvCERlF2dcn2wqJw+CreTkkQ2R
-----END CERTIFICATE-----

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

View certificate JSON

Registration / WHOIS →DNS records →