1. General Results, most used to calculate the result A name "mmolb.com" is domain, public suffix is ".com", top-level-domain is ".com", top-level-domain-type is "generic", tld-manager is "VeriSign Global Registry Services", num .com-domains preloaded: 89449 (complete: 231048) A Good: All ip addresses are public addresses Warning: Only one ip address found: mmolb.com has only one ip address. Warning: Only one ip address found: www.mmolb.com has only one ip address. Warning: No ipv6 address found. Ipv6 is the future with a lot of new features. So every domain name should have an ipv6 address. See https://en.wikipedia.org/wiki/IPv6: mmolb.com has no ipv6 address. Warning: No ipv6 address found. Ipv6 is the future with a lot of new features. So every domain name should have an ipv6 address. See https://en.wikipedia.org/wiki/IPv6: www.mmolb.com has no ipv6 address. A Good: No asked Authoritative Name Server had a timeout A Good: destination is https A Good: No cookie sent via http. HSTS-Preload-Status: unknown. Domain never included in the Preload-list. Check https://hstspreload.org/ to learn some basics about the Google-Preload-List. A Good: All urls with http status 200/404 have a complete Content-Type header (MediaType / MediaSubType + correct charset) A http://mmolb.com/ 3.139.28.43 https://mmolb.com/ Correct redirect http - https with the same domain name A http://www.mmolb.com/ 3.139.28.43 https://www.mmolb.com/ Correct redirect http - https with the same domain name B https://mmolb.com/ 3.139.28.43 Missing HSTS-Header B https://www.mmolb.com/ 3.139.28.43 Missing HSTS-Header B https://mmolb.com/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de Missing HSTS-Header B https://www.mmolb.com/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de Missing HSTS-Header B https://mmolb.com/ 3.139.28.43 PHPSESSID=too25r0vpomnd6l96hda45m1cs; path=/ Cookie sent via https, but not marked as secure B https://www.mmolb.com/ 3.139.28.43 PHPSESSID=am1sbp6kqm1015n4oekasnlc39; path=/ Cookie sent via https, but not marked as secure B https://3.139.28.43/ 3.139.28.43 PHPSESSID=dmc3t161jhjei4ao8ej0ov4i5p; path=/ Cookie sent via https, but not marked as secure B https://mmolb.com/ 3.139.28.43 PHPSESSID=too25r0vpomnd6l96hda45m1cs; path=/ Cookie without a SameSite-Attribute. Possible values are: Strict/Lax/None. Cookie may not work as expected, if "None" is wanted, but browsers use "Lax" as default value. B https://www.mmolb.com/ 3.139.28.43 PHPSESSID=am1sbp6kqm1015n4oekasnlc39; path=/ Cookie without a SameSite-Attribute. Possible values are: Strict/Lax/None. Cookie may not work as expected, if "None" is wanted, but browsers use "Lax" as default value. B https://3.139.28.43/ 3.139.28.43 PHPSESSID=dmc3t161jhjei4ao8ej0ov4i5p; path=/ Cookie without a SameSite-Attribute. Possible values are: Strict/Lax/None. Cookie may not work as expected, if "None" is wanted, but browsers use "Lax" as default value. C Error - no preferred version www or non-www. Select one version as preferred version, then add a redirect https + not-preferred version to https + preferred version. Perhaps in your port 443 vHost something like "RewriteEngine on" + "RewriteCond %{SERVER_NAME} = example.com" + "ReWriteRule ^ https://www.example.com%{REQUEST_URI} [END,QSA,R=permanent]" (three rows, without the "). That should create a redirect https + example.com ⇒ https + www.example.com. Or switch both values to use the non-www version as your preferred version. C Error - more then one version with Http-Status 200. After all redirects, all users (and search engines) should see the same https url: Non-www or www, but not both with http status 200. N https://3.139.28.43/ 3.139.28.43 Error - Certificate isn't trusted, RemoteCertificateNameMismatch, RemoteCertificateChainErrors Info: Checking all ip addresses of that domain without sending the hostname only one certificate found. Checking all ip addresses and sending the hostname only one certificate found. Both certificates are different. So that domain requires Server Name Indication (SNI), so the server is able to select the correct certificate.: Domain mmolb.com, 1 ip addresses. Info: Checking all ip addresses of that domain without sending the hostname only one certificate found. Checking all ip addresses and sending the hostname only one certificate found. Both certificates are different. So that domain requires Server Name Indication (SNI), so the server is able to select the correct certificate.: Domain www.mmolb.com, 1 ip addresses. B No _mta-sts TXT record found (mta-sts: Mail Transfer Agent Strict Transport Security - see RFC 8461). Read the result of server-daten.de (Url-Checks, Comments, Connections and DomainServiceRecords) to see a complete definition. Domainname: _mta-sts.mmolb.com 2. Header-Checks F mmolb.com 3.139.28.43 Content-Security-Policy Critical: Missing Header: F mmolb.com 3.139.28.43 X-Content-Type-Options Critical: Missing Header: F mmolb.com 3.139.28.43 Referrer-Policy Critical: Missing Header: F mmolb.com 3.139.28.43 Permissions-Policy Critical: Missing Header: F www.mmolb.com 3.139.28.43 Content-Security-Policy Critical: Missing Header: F www.mmolb.com 3.139.28.43 X-Content-Type-Options Critical: Missing Header: F www.mmolb.com 3.139.28.43 Referrer-Policy Critical: Missing Header: F www.mmolb.com 3.139.28.43 Permissions-Policy Critical: Missing Header: 3. DNS- and NameServer - Checks A Info:: 16 Root-climbing DNS Queries required to find all IPv4- and IPv6-Addresses of 4 Name Servers. A Info:: 16 Queries complete, 16 with IPv6, 0 with IPv4. A Good: All DNS Queries done via IPv6. Ok (4 - 8):: An average of 4.0 queries per domain name server required to find all ip addresses of all name servers. A Info:: 4 different Name Servers found: ns-1083.awsdns-07.org, ns-1911.awsdns-46.co.uk, ns-278.awsdns-34.com, ns-595.awsdns-10.net, 4 Name Servers included in Delegation: ns-1083.awsdns-07.org, ns-1911.awsdns-46.co.uk, ns-278.awsdns-34.com, ns-595.awsdns-10.net, 4 Name Servers included in 1 Zone definitions: ns-1083.awsdns-07.org, ns-1911.awsdns-46.co.uk, ns-278.awsdns-34.com, ns-595.awsdns-10.net, 1 Name Servers listed in SOA.Primary: ns-278.awsdns-34.com. A Good: Only one SOA.Primary Name Server found.: ns-278.awsdns-34.com. A Good: SOA.Primary Name Server included in the delegation set.: ns-278.awsdns-34.com. A Good: Consistency between delegation and zone. The set of NS records served by the authoritative name servers must match those proposed for the delegation in the parent zone. Ordered list of name servers: ns-1083.awsdns-07.org, ns-1911.awsdns-46.co.uk, ns-278.awsdns-34.com, ns-595.awsdns-10.net A Good: All Name Server Domain Names have a Public Suffix. A Good: All Name Server Domain Names ending with a Public Suffix have minimal one IPv4- or IPv6 address. A Good: All Name Server ip addresses are public. A Good: Minimal 2 different name servers (public suffix and public ip address) found: 4 different Name Servers found A Good: All name servers have ipv4- and ipv6-addresses.: 4 different Name Servers found A Good: Name servers with different Top Level Domains / Public Suffix List entries found: 4 Name Servers, 4 Top Level Domains: org, net, com, co.uk A Good: Name Servers with different domain names found.: 4 different Domains found A Good: Name servers with different Country locations found: 4 Name Servers, 3 Countries: GB, IE, US A Info: Ipv4-Subnet-list: 4 Name Servers, 1 different subnets (first Byte): 205., 1 different subnets (first two Bytes): 205.251., 4 different subnets (first three Bytes): 205.251.193., 205.251.194., 205.251.196., 205.251.199. A Good: Name Server IPv4-addresses from different subnet found: A Info: IPv6-Subnet-list: 4 Name Servers with IPv6, 1 different subnets (first block): 2600:, 1 different subnets (first two blocks): 2600:9000:, 4 different subnets (first three blocks): 2600:9000:5301:, 2600:9000:5302:, 2600:9000:5304:, 2600:9000:5307:, 4 different subnets (first four blocks): 2600:9000:5301:1600:, 2600:9000:5302:5300:, 2600:9000:5304:3b00:, 2600:9000:5307:7700: A Good: Name Server IPv6 addresses from different subnets found. A Good: Nameserver supports TCP connections: 8 good Nameserver A Good: Nameserver supports Echo Capitalization: 8 good Nameserver A Good: Nameserver supports EDNS with max. 512 Byte Udp payload, message is smaller: 8 good Nameserver A Good: Nameserver has passed 10 EDNS-Checks (OP100, FLAGS, V1, V1OP100, V1FLAGS, DNSSEC, V1DNSSEC, NSID, COOKIE, CLIENTSUBNET): 8 good Nameserver A Good: All SOA have the same Serial Number Warning: No CAA entry with issue/issuewild found, every CAA can create a certificate. Read https://en.wikipedia.org/wiki/DNS_Certification_Authority_Authorization to learn some basics about the idea of CAA. Your name server must support such an entry. Not all dns providers support CAA entries. 4. Content- and Performance-critical Checks A Good: All checks /.well-known/acme-challenge/random-filename without redirects answer with the expected http status 404 - Not Found. Creating a Letsencrypt certificate via http-01 challenge should work. If it doesn't work: Check your vHost configuration (apachectl -S, httpd -S, nginx -T). Every combination of port and ServerName / ServerAlias (Apache) or Server (Nginx) must be unique. Merge duplicated entries in one vHost. If you use an IIS, extensionless files must be allowed in the /.well-known/acme-challenge subdirectory. Create a web.config in that directory. Content: <configuration><system.webServer><staticContent><mimeMap fileExtension="." mimeType="text/plain" /></staticContent></system.webServer></configuration>. If you have a redirect http ⇒ https, that's ok, Letsencrypt follows such redirects to port 80 / 443 (same or other server). There must be a certificate. But the certificate may be expired, self signed or with a not matching domain name. Checking the validation file Letsencrypt ignores such certificate errors. Trouble creating a certificate? Use https://community.letsencrypt.org/ to ask. A Good: No https + http status 200 with inline CSS / JavaScript found A Good: Every https result with status 200 has a minified Html-Content with a quota lower then 110 %. https://mmolb.com/ 3.139.28.43 Warning: Https connections (Standard Port 443) found without support of the http/2 protocol via ALPN. Http/2 is the new Http-Version (old: http 1.1) with some important new features. Update your server software so http/2 is available. Only one TCP-connection per Server (that's a performance boost), Header-Compression and Server Pushs are available. Domain Sharding and Inline-CSS/Javascript shouldn't used with http/2. https://www.mmolb.com/ 3.139.28.43 Warning: Https connections (Standard Port 443) found without support of the http/2 protocol via ALPN. Http/2 is the new Http-Version (old: http 1.1) with some important new features. Update your server software so http/2 is available. Only one TCP-connection per Server (that's a performance boost), Header-Compression and Server Pushs are available. Domain Sharding and Inline-CSS/Javascript shouldn't used with http/2. https://3.139.28.43/ 3.139.28.43 Warning: Https connections (Standard Port 443) found without support of the http/2 protocol via ALPN. Http/2 is the new Http-Version (old: http 1.1) with some important new features. Update your server software so http/2 is available. Only one TCP-connection per Server (that's a performance boost), Header-Compression and Server Pushs are available. Domain Sharding and Inline-CSS/Javascript shouldn't used with http/2. Warning: CSS / JavaScript found without GZip support. Send these ressources with GZip. 2 external CSS / JavaScript files without GZip found - 0 with GZip, 2 complete Warning: CSS / JavaScript files with a missing or too short Cache-Control header found. Browsers should cache and re-use these files. 3 external CSS / JavaScript files without Cache-Control-Header, 0 with Cache-Control, but no max-age, 0 with Cache-Control max-age too short (minimum 7 days), 0 with Cache-Control long enough, 3 complete. A Good: All checked attribute values are enclosed in quotation marks (" or '). A Info: No img element found, no alt attribute checked A Good: Domainname is not on the "Specially Designated Nationals And Blocked Persons List" (SDN). That's an US-list of individuals and companies owned or controlled by, or acting for or on behalf of, targeted countries. It also lists individuals, groups, and entities, such as terrorists and narcotics traffickers designated under programs that are not country-specific. Collectively, such individuals and companies are called "Specially Designated Nationals" or "SDNs." Their assets are blocked and U.S. persons are generally prohibited from dealing with them. So if a domain name is on that list, it's impossible to create a Letsencrypt certificate with that domain name. Check the list manual - https://www.treasury.gov/resource-center/sanctions/sdn-list/pages/default.aspx https://mmolb.com/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 3.787 seconds Warning: 404 needs more then one second https://www.mmolb.com/.well-known/acme-challenge/check-your-website-dot-server-daten-dot-de 3.823 seconds Warning: 404 needs more then one second A Duration: 251580 milliseconds, 251.580 seconds