Here is the email I received.
If you registered (Correction: based on comments this may be for attendees not just registration) to watch Microsoft Build 2020 Virtual conference you may have received one.
Subject Line: Microsoft employee store discount from Microsoft Build
We're sharing our employee discount with you!
50-80% off MSRP on all things digital. This includes Windows, Office, Xbox Game Pass, and Xbox Live subscriptions.
Receive $5 off your first purchase. You can purchase a maximum of $250 at heavily discounted employee prices.
Thanks for attending Microsoft Build!
Here are your login details:
Pass Id: (The contact email address associated with your registration)
This offer expires August, 1st 2020.
PS the family subscription is $20 (- $5 for first purchase ) -> $15