How many of you have M365 established as an internal as well as external collaboration platform? Please share your experiences and "gotchas". Would also like to know if you decided not to use M365 for external collaboration (and split the environment between internal vs external) for some reasons. Our strategy is to use M365 services (SPO, Teams, Forms etc) to provide collaboration and productivity services to both internal employees and external partners. We collaborate with many other organizations on co-authoring research papers, project related activities, and regular business activities.  

We use M365 internally but tend to use zoom externally. I tend to think of M365 as a collaboration tool but Zoom as a meeting tool. So it has been easier to have a meeting using zoom with people who use different technologies for their daily work. Internally, since we all use M365, it has been easier to use it for both meetings and collaboration. I also notice that Teams is more often used for a spontaneous meeting, such as replacing what would have been a quick phone call or a quick walk down the hall, whereas Zoom is more often used when the meeting is scheduled.

M365 has a good set of tools enabling collaboration. I have used it in the past and we also use it currently to enable seamless collaboration (sync and async) both internally and externally.