Custom add-ins, VBA projects, ancient APIs that remain for legacy reasons, all mean this will be a tricky application to replace.
What if Microsoft replaces the Windows version with a similarly rebuilt product? Perhaps it will but the difficulty is that Outlook is baked into the Windows ecosystem and forms part of workflows, some automated with COM technology, that will break if Microsoft replaces it. Lastly, the problem of Outlook on Windows being different from Outlook on Mac will get worse. Teams integration will also be strong and Microsoft has demonstrated features like converting an event to a Teams meeting, handy in times of lockdown. Second, Outlook Mac will be focused on cloud, especially Office 365, though it also already has good support for Google mail. This is not a high bar: Outlook on Windows is a mess from a user interface perspective, and has dialogues buried within that have not changed for decades. Outlook 2016 for Mac now lets you send emails later, track messages & more. First, it will be the best Outlook yet, perhaps on any platform, in terms of appearance and design. To be certain: An out of office reply is a standard part of good email. Microsoft has not specified a release date for the new Outlook Mac but a few things are clear.
The current preview is not fully usable, but fortunately switching back is quick The problem of Outlook on Windows being different from Outlook on Mac will get worse
