Microsoft Teams, does not need any introduction as there is a lot marketing going on 🙂
Team built on core services are Exchange and SharePoint and Skype too. As soon as you create a new Team for collaboration with you colleagues background services start spinning exchange group mailbox and SharePoint libraries for you and in few minutes you are ready to collaborate in real-time which even allows to make calls from any device (I like it on my iOS).
So what is external collaboration and how to control it?
You can invite external parties to contribute and collaborate in Microsoft Teams or to be specific you can invite them in Channels within your team. If you don’t change the default setting, it open to anyone means anyone can send EMAILS your channels once they know the SMTP ALIAS. So if you don’t like it and if you have some business requirement which may not want to you keep it open for all, this video while show you how to control the EXTERNAL SHARING.