Sit in my DeLorean, and let me take you for a ride. It is the summer of 2005, and Zimbra Collaboration Suite was just released. It promises to migrate your Microsoft Exchange-powered e-mail and calendar to more affordable server software while maintaining compatibility. Microsoft Exchange is very important in business, and many companies default to it. Many companies don't trust external servers (cloud services), and they have it as company policy to host all servers on-premise. But sometimes expenses are optimized, and compromises are being made. I say compromise because Zimbra doesn't really have an answer to Microsoft Outlook, so although you might have saved money by switching Microsoft Exchange Server with Zimbra, you still need to purchase Microsoft Office or Microsoft 365 to get access to Microsoft Outlook desktop software which all your users come to expect on their computers.
I have been working with system integrator companies for 20 years, and in all my professional life, I have seen sys admins attempting to replace Microsoft Outlook, and failing, so many times that I have lost count. The key takeaway is that users are used to it. They do not want an alternative, which places Microsoft in a cozy position.
