Blocked account and its verification

I got an email from "*** Email address is removed for privacy ***" that my account is blocked due to suspicious mail activity. It is said that my email is used to spread spam emails. I am very curious about why this happened, because I run Kaspersky PURE 3.0 on my PC and Kaspersky Internet Security for Mac in my MacBook Pro. I really struggle everyday to keep my PCs and phones safe! And I never log in to any of my accounts other than my stuff and on my network.

Actually, I need someone to confirm or not whether the "*** Email address is removed for privacy ***" is a real supporting email service from Microsoft.

I was searching for it, but I found no results.

The actions taken so far are:

1. Verified my account, by clicking the link provided on the email I got. I signed in and applied the security code I got on my phone.

2. Changed the password.

P.S. I know exactly the danger behind links on a email, but I checked it over and over again, and found nothing suspicious. The only suspicious thing was since I had verified my account, I could not access my emails. I have had to sign-out and sign-in again, in order to access my emails. And then, I changed my password again.