Ms Teams - External Chat
With Microsoft Teams, you can reach out to other Microsoft M365 users and chat directly with them.
Option 1: Be invited to their tennant, and have to switch between the tennants in the top right corner (really annoying)
Option 2: Paste their emails address and use eg. scott@contoso.com (EXTERNAL). The external part means you are messaging someone OUT of your organisation - Way easier, but needs both companies to keep it allowed in settings (some IT Admins switch it off).
