There are many environments where people don’t have a choice but to maintain what is in production.
Whether or not viable alternatives exist, those alternatives don’t magically change org structure, office politics, budget, current business priorities, etc.
Bottom line: many people managing exchange don’t have the luxury of evaluating this problem in terms of alternatives.
I don’t know any that come close in functionality, configurability, and maintainability. Exchange scales from a one-person handyman to Fortune 500 without a hitch, it comes with an office suite and cloud storage space, you find specialists for it on every corner, and it mostly just works. That’s pretty hard to beat, even if I’m personally more than unhappy to be so dependent on Microsoft, a US product, and closed-source software; there’s just not much I can do about it.
Thing is, I’ve been doing this since before Exchange Online, I know.
People used a few different groupware solutions, worked with bespoke IMAP installations on Linux servers, or (the vast majority) had on-premises Exchange servers running locally. It all required lots of tech wizardry, tinkering, duct tape and hope.
It was a long while before we had turn-key solutions, and you needed actually knowledgeable folks running your IT operations, and nothing was as fully integrated or cheaply available as Exchange Online.
a.k.a. i think you're missing the point. It's ok. You want knowledgeable people running your key infra. Outsourcing that to a company that doesn't respect privacy seems to be shooting oneself in the foot.
No, sorry, I think you're missing the point. There is one Hotmail, and a million businesses that need reliable email. I don’t want to outsource my key infra, but that’s the only viable option for most companies.
Getting email right requires lots of infra expertise, steady financial expenses, and time. Most companies just don’t have any of these available, and it makes zero economic sense as well if a product like Microsoft 365 exists.
Whether or not viable alternatives exist, those alternatives don’t magically change org structure, office politics, budget, current business priorities, etc.
Bottom line: many people managing exchange don’t have the luxury of evaluating this problem in terms of alternatives.