Exchange represents over 50% of corporate email accounts globally, and 15% of these are hosted. These are BIG numbers and Apple will eventually respond to the issue. I'm not an IT guy but I suspect there is some gamesmanship between MSFT and Apple behind the scenes trying to determine who is at fault.
In my little startup world (I am a VC on the west coast), Apple has something like 90% market share. These are very influential users, many of whom would still be running exchange-based email.
My pathetic work around is as follows: for Exchange email I'm running Outlook 365 (which doesn't like icloud email). And for icloud email I'm running Mail (which no longer likes Exchange email). And I keep my iphone by my side because it receives everything first.
Be articulate and respectful. If you come across as a whiny crank, you will be ignored and hurt your cause.
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