IWX
Accounts
Microsoft Console
External Tools
EchoReply
DNS,Whois,IP,Geo,365,MAC,SN
DNS Checker
DNS Propagation
WebSite Checker
internet.nl
AADInternals
365 Tenant Intelligence
O365.Rocks
365 Tenant Checker
IP Location
GeoIP
DownDetector
365 Maps
License Matrix
Cheat.sh
CLI Cheats
Qualys
SSL Checker
Sucuri
Web AV Scanner
Ubiquiti
Resource Calculator
Mail Tester
Deliverability
Google Header Analyzer
M$ Header Analyzer
Google's Phishing Quiz
Good to train users