Now how do I collaborate with the people in the other 3 orgs I work with who use O365?

> It's not really about open source versus priority, it's about open source quality, which quite frankly isn't there.

...

> Show me an open source O365 equivalent that scales to the 10,000 seats in my org.

...

> Now how do I collaborate with the people in the other 3 orgs I work with who use O365?

I hope you used an excavator, moving those goalposts.

Not really. The reason those orgs use O365 is that there isn't a better option with the same ROI and staffing requirements. It because a defacto standard because no one offered anything better.

(I will add I despise it to the core, but I know why people use it)

> The reason those orgs use O365 is that there isn't a better option with the same ROI and staffing requirements. It because a defacto standard because no one offered anything better.

As you pointed out once the goal posts shifted, the reason they use Microsoft is because Microsoft is notoriously incompatible with anyone but Microsoft, but also ubiquitous.