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

mail.apptocloud.com · 185.119.216.245:443

Verified

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

Subject
CN=autodiscover.apptocloud.com
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-08-22T01:23:02+00:00
Expires
2026-11-20T01:23:01+00:00
Days remaining
31
Serial (hex)
0663C1DEF3926753A2546161A74C5BECFAA6
Signature
RSA-SHA256
Public key
RSA 3072

Subject alternative names (SAN)

DNS:autodiscover.apptocloud.com, DNS:autodiscover.apptocloud.cz, DNS:autodiscover.icewarp.cz, DNS:mail.appsec.cz, DNS:mail.apptocloud.com, DNS:mail.apptocloud.cz, DNS:mail.icewarp.cz

SHA-256 fingerprint

34:F3:30:F0:4A:19:E2:00:3C:AB:E3:09:42:B4:93:FB:98:1A:FC:9D:B8:B4:3A:B0:1D:89:44:6F:38:99:CE:62
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
39:1B:E3:B4:77:C4:2C:37:45:5C:F4:58:B1:4E:59:1F:89:E3:46:56
authorityKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
authorityInfoAccess
CA Issuers - URI:http://yr1.i.lencr.org/
subjectAltName
DNS:autodiscover.apptocloud.com, DNS:autodiscover.apptocloud.cz, DNS:autodiscover.icewarp.cz, DNS:mail.appsec.cz, DNS:mail.apptocloud.com, DNS:mail.apptocloud.cz, DNS:mail.icewarp.cz
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/39.crl
ct_precert_scts
Signed Certificate Timestamp: Version : v1 (0x0) Log ID : D7:6D:7D:10:D1:A7:F5:77:C2:C7:E9:5F:D7:00:BF:F9: 82:C9:33:5A:65:E1:D0:B3:01:73:17:C0:C8:C5:69:77 Timestamp : Aug 22 02:21:32.906 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:8B:6E:29:C8:5A:AA:EF:C3:2C:4D:98: D0:83:0F:8B:E1:86:6F:70:67:B2:A2:CD:5C:A6:D4:ED: B1:D1:97:2E:BC:02:20:10:6E:2F:EF:63:22:71:E4:7D: BB:08:B2:11:8F:49:98:E6:FC:5C:46:80:C2:40:58:89: 20:E9:33:38:AC:D0:E2 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : 46:AF:86:3D:3B:3E:E5:9F:A5:77:DE:A8:24:5D:36:B0: D9:ED:22:A2:23:F4:61:77:41:22:94:52:EE:95:50:5F Timestamp : Aug 22 02:21:33.152 2026 GMT Extensions: 00:00:05:00:18:C7:9D:35 Signature : ecdsa-with-SHA256 30:44:02:20:0D:B1:32:95:59:5D:29:14:40:E2:4A:6A: D8:F3:B0:A2:64:20:29:67:6E:2A:4D:45:01:11:DD:AD: 81:7D:A0:B1:02:20:30:A0:D5:8D:80:A9:66:91:3C:DC: E7:AF:6B:F7:A2:EE:88:19:99:8E:9F:05:8F:18:9E:2C: 09:D2:47:BF:83:6A
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-10-19T03:10:17+00:00

Server-presented chain · 2 additional certificates

Chain certificate 1

Subject
C=US O=Let's Encrypt CN=YR1
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
684
Serial (hex)
A20253F15F2691C05DC1CE13B9BCCA4E
Signature
RSA-SHA256
Public key
RSA 2048

Subject alternative names (SAN)

No SAN extension was presented.

SHA-256 fingerprint

13:94:96:34:D9:9C:D6:FD:6A:A8:0B:C0:34:FE:FA:CC:EB:19:69:FE:EF:98:65:86:71:3E:CD:BB:05:75:8D:3F
Certificate extensions & PEM
keyUsage
Digital Signature, Certificate Sign, CRL Sign
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:TRUE, pathlen:0
subjectKeyIdentifier
1F:2F:35:BE:46:14:82:CD:40:B1:AE:79:2C:55:78:FA:F7:D4:68:FB
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
2145
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

Registration / WHOIS →DNS records →