DNS

IntoDNS checks the health and configuration and provides DNS report and mail servers report. And provides suggestions to fix and improve them, with references to protocols’ official documentation.

https://dnschecker.org/

DNS records and worldwide DNS propagation checker

Do a quick DNS propagation lookup for any domain name and check DNS data collected from all location for confirming that the website is completely propagated or not worldwide.

Mail

Mxtoolbox

https://mxtoolbox.com/

This test will list MX records for a domain in priority order. The MX lookup is done directly against the domain’s authoritative name server, so changes to MX Records should show up instantly. You can click Diagnostics , which will connect to the mail server, verify reverse DNS records, perform a simple Open Relay check and measure response time performance. You may also check each MX record (IP Address) against 105 DNS based blacklists . (Commonly called RBLs, DNSBLs)

Microsoft Remote Connectivity Analyzer

https://testconnectivity.microsoft.com/

Message Header Analyzer

https://mha.azurewebsites.net/

SSL

Decoder.link

https://decoder.link/

SSL Online tools by Namecheap

SSL Server Test

https://www.ssllabs.com/ssltest/
This free online service performs a deep analysis of the configuration of any SSL web server on the public Internet. Please note that the information you submit here is used only to provide you the service. We don’t use the domain names or the test results, and we never will.

SSL/TLS Capabilities of Your Browser

https://clienttest.ssllabs.com:8443/ssltest/viewMyClient.html

Reputation

Cisco Talos

https://talosintelligence.com/reputation_center

IPVOID – Blacklist Check

https://www.ipvoid.com/

https://www.ipvoid.com/ip-blacklist-check/

Scan an IP address through multiple DNS-based blacklists (DNSBL) and IP reputation services, to facilitate the detection of IP addresses involved in malware incidents and spamming activities. This service checks in real-time an IP address through more than 80 IP reputation and DNSBL services. This service is built with the IP Reputation API by APIVoid.