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.alterra.host · 149.50.122.34:443

Verified

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

Subject
CN=mail.alterra.host
Issuer
C=US O=Let's Encrypt CN=YR1
Valid from
2026-08-06T16:29:30+00:00
Expires
2026-11-04T16:29:29+00:00
Days remaining
30
Serial (hex)
0554DF7ED2568F11E3F17AC6EFB5B1DCFA1D
Signature
RSA-SHA256
Public key
RSA 4096

Subject alternative names (SAN)

DNS:autodiscover.alterra.host, DNS:mail.alterra.host

SHA-256 fingerprint

7F:5A:C0:1B:D0:83:97:FC:57:92:F9:86:74:11:86:45:B7:48:44:91:AC:AB:8B:21:15:06:D5:A7:D8:8A:30:3B
Certificate extensions & PEM
keyUsage
Digital Signature, Key Encipherment
extendedKeyUsage
TLS Web Server Authentication
basicConstraints
CA:FALSE
subjectKeyIdentifier
ED:BC:0B:D7:F9:B8:DB:D6:CA:C2:D2:0B:6D:CF:5A:19:ED:EC:77:5D
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.alterra.host, DNS:mail.alterra.host
certificatePolicies
Policy: 2.23.140.1.2.1
crlDistributionPoints
Full Name: URI:http://yr1.c.lencr.org/30.crl
ct_precert_scts
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 : Aug 6 17:28:00.986 2026 GMT Extensions: 00:00:05:00:32:15:54:90 Signature : ecdsa-with-SHA256 30:44:02:20:2F:BF:91:3D:77:99:36:34:B0:19:FD:E3: BE:FE:00:B1:D1:93:06:A0:84:62:77:78:FA:BF:02:87: 94:80:7B:2F:02:20:29:AF:00:0F:8B:7D:BF:46:D6:B0: A0:F0:7D:42:71:77:6E:48:FC:1B:74:4E:A9:C6:6C:AF: A4:9D:4D:27:DE:73 Signed Certificate Timestamp: Version : v1 (0x0) Log ID : C2:31:7E:57:45:19:A3:45:EE:7F:38:DE:B2:90:41:EB: C7:C2:21:5A:22:BF:7F:D5:B5:AD:76:9A:D9:0E:52:CD Timestamp : Aug 6 17:28:06.254 2026 GMT Extensions: none Signature : ecdsa-with-SHA256 30:45:02:21:00:EF:2B:CB:1A:22:A1:66:85:80:48:E9: 73:53:07:37:37:2F:EB:3A:1A:7A:53:93:D6:00:04:D4: 8F:44:BC:BE:3E:02:20:36:49:F0:FF:EB:1D:CF:5B:CA: 0D:74:B0:FA:19:61:A1:FB:2A:EA:12:DA:0C:16:49:40: 2A:C6:89:67:B0:27:91
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Cipher: TLS_AES_256_GCM_SHA384 · Checked 2026-10-04T17:44:58+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
699
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
2160
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-----
MIIF9DCCA9ygAwIBAgIRAPJLbRf52a18scn+p4eCaZ8wDQYJKoZIhvcNAQELBQAw
TzELMAkGA1UEBhMCVVMxKTAnBgNVBAoTIEludGVybmV0IFNlY3VyaXR5IFJlc2Vh
cmNoIEdyb3VwMRUwEwYDVQQDEwxJU1JHIFJvb3QgWDEwHhcNMjYwNTEzMDAwMDAw
WhcNMzIwOTAyMjM1OTU5WjAuMQswCQYDVQQGEwJVUzENMAsGA1UEChMESVNSRzEQ
MA4GA1UEAxMHUm9vdCBZUjCCAiIwDQYJKoZIhvcNAQEBBQADggIPADCCAgoCggIB
ANvGJnN78CTJdWL3+eGfsLN5TrNBJs+VH9hRXqRbwxu9sGNiB0BD1fcOxbSUQCJI
M1xE13Db+5Cw1w0s0EBYsvuIP/6joF0w8cuImbgR1OGgYbSQ4OpzI+DG8SGuTlcE
873OCS+kh3srlo6vl43M5OJg4Aeo1sfHp6kTJDoIiFBNJAY+OKfX/FUvYKuhjT+n
o49lmqmupSBI5PkBQiqrEGtWU5uxU/cQWHGu8jSjFBznZqvbNPLMXMLFxCb3WTfr
JBXXjqvWG+v4bjzxjjeAtOlU7qarRDvNOyAuQYLln904M+faKx8hnLCpJ15ZqaEg
cNlY+9MMWcC5yvL2A2j3l9+2buggZX+dOE91zYmIdawTvSZuVvlbRrAlLxIB6pwM
BjneXCjYQ8+3BCCjssbSNpZU3hTcBDdhfAlEDlYr6pEatnMdmDT5BqnKC92bd0Eh
M1fbLHioLccLCuievT8ZkPhZrq7Mii7gNXAcUEAR8+lzYal+9zTg7C5DALyVOeG/
CqfRAMn1KSHCR0NSA6P8tn/mGRlnCct5rtVCLnVySVpU6H1qGg3DgTOuskf8eahT
MiYbI5ezPJmO5ertalskQ1utp74+eDy92PI4ftHKTbq9IWhH4YZKh3WnJEIt+oQv
lYZbY8tpEroKrFB6PFGzrJIDRyts4HqvuH52RFj2zv/BAgMBAAGjgeswgegwDgYD
VR0PAQH/BAQDAgEGMBMGA1UdJQQMMAoGCCsGAQUFBwMBMA8GA1UdEwEB/wQFMAMB
Af8wHQYDVR0OBBYEFN7nW2DQIm1AKH0/DQH+pLVStFGUMB8GA1UdIwQYMBaAFHm0
WeZ7tuXkAXOACIjIGlj26ZtuMDIGCCsGAQUFBwEBBCYwJDAiBggrBgEFBQcwAoYW
aHR0cDovL3gxLmkubGVuY3Iub3JnLzATBgNVHSAEDDAKMAgGBmeBDAECATAnBgNV
HR8EIDAeMBygGqAYhhZodHRwOi8veDEuYy5sZW5jci5vcmcvMA0GCSqGSIb3DQEB
CwUAA4ICAQA8spSI95KKfn2W6GMmDpHBJSPaLbsS3W93cijJCRCYAc1fsJgL1FIL
7C0C9ecPOdcwB2fi0Dk2p94j9iTJCxmt5CFSKLRWwnXT2MMSXexVxqoVB79BdWPx
VXETkVme/qYSAuKVHh5Ps+5BixgmwS1JkjSAc+MfrUbNssVEEnH0aEiAh+rotXAV
JSP/Ye7LJPEwD9DWG72vVWbhAcuOf5OLjz57Ctk7MgQHynZ7+PlHJtajroCaIbtC
r6tcZZaAwUQm+jQyeWdV+2hv9deOYFmKeQyjjcSrN5Nadrw+L9DZJLbA1HqeNvLh
BgqpP0fvJq2N6EtD574N6eMI7uMsJTnji2UDz9el5XLSv9fqJMuDQtYVb2oTNoKp
oUqhxPVC0aq4eG5MESaIdn8b5ZGSSeAJLMHXljEdlNza+ncfkviXk1POLnnFdvx8
/gk6M374WbLWFXw8N141B/Rl/tINGfl1TxOIiqtiMYkL02RSGb1kq34BL9NPP27z
RGMuHGnzS3hFIrRTfKxrzUZ9RzQWzEG3K6fJ3r2nqSltkeytis9DIBoFY9VmVyjL
M71DMi+y1+TRSJVClEMwvA4yL++7q9XZx5r5wBRWB4kQTKH5qyoZnDw7iiuh1lID
yDFx8r7i9vIJU5HS3moZLkYWAOilMaV9N56A9Bgb6dNcHkvg3NoaYA==
-----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 →