It might seem strange but you can now use Microsoft Teams for free with a Gmail address. Yes, Gmail.
Teams is Microsoft's collaboration tool for enterprises, small businesses and now for individuals. It allows you to create a team of people collaborating on a project. It also contains the ability to have video conferencing.
Up until now the "free tier" required you to have Microsoft account based on one of the free Microsoft email addresses such as Hotmail, Outlook.com or live.com. A new step by step video allows you to create a Team based on a Gmail address.
Teams is becoming an application platform of it's own, linking into a variety of Microsoft services and third party cloud applications. I am sure the idea is to lock people into Teams and then sell other subscription services. However, as a free service now people can benefit from Microsoft's experience in the area of business applications, privacy and security.