O365_emailvalidator is a script to validate if an e-mail exists (is valid) or not in the Microsoft 365.
It employs a technique that queries the URL: https://tenantname-my.sharepoint.com/personal//_layouts/15/onedrive.aspx.
The best part? It remains undetectable by the blue team and there is no blocking or rate limit by MS! 😎
You need the Tenant name, major part is companyname+corp or companyname+country_code or just company name. You can try search in google:
"Companyname" site:sharepoint.com
Example: Company name is CrazyPiffaretti and is located in Switzerland
Probably names of tenants:
- Crazypiffaretticorp
- Crazypiffaretti
- Crazypiffarettich (ch is the code of switzerland)