Describe how OSINT can be used to supplement your organizational collection plan, identify 10 sites that can be used to research sites/domains for: legitimacy sender verification

 
Task: Describe how OSINT can be used to supplement your organizational collection plan, identify 10 sites that can be used to research sites/domains for:

legitimacy
sender verification
list of domains (country codes/domains/extensions, organization domains, other IOC (indicators of compromise) that might need to be researched)

 
https://github.com/dthroner/Hacking/blob/master/Google%20Hacking%20For%20Penetration%20Testers-Syngress%20(2015).pdf

https://www.youtube.com/watch?v=WQo03MJG0m4