Using classic Outlook for Windows in business environments
In my Hotmail/Outlook.com I have it set to receive mail from Contact's only for many years and today it stopped working. Getting nearly 100+ phishing attempts per hour!
Microsoft at least acknowledge the issue.
@Sajjad747 your instructions are worthless! The issue is at the "server" end not the webmail client settings. Had you actually read the posts you might understand that.