Meetings with external Guest users in Microsoft Teams
If you have the Teams Desktop client installed, Outlook will see an add-in for Teams, which will automatically be enabled.
Open Outlook and click on the teams logo on top
Enter in your invitation message in the body
Who can attend these meetings?
1) A User With No Microsoft Account at all – Just Need An Email
2) A User With any Office365 account, as a Guest User
3) Anyone with a Phone