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.
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.
Mxtoolbox
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
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/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.
Proofpoint
https://ipcheck.proofpoint.com/
IBM X-Force Exchange
https://exchange.xforce.ibmcloud.com/
Spamhaus
https://www.spamhaus.org/lookup/
Barracuda central
https://www.barracudacentral.org/lookups
Symantec IP Reputation Investigation
https://ipremoval.sms.symantec.com/ipr/lookup
IP Reputation with IPQualityScore
https://www.ipqualityscore.com/free-ip-lookup-proxy-vpn-test
VirusTotal URL and IP search
IP Analyzer
AbuseIPDB
https://www.abuseipdb.com/check/
Passwords
Have I Been Pwned?
Dashlane-sponsored How Secure Is My Password?