This issue is 100% outlook. It is not an Exchange issue. It seems that the system calls that Outlook is utilizing are either no longer supported or have changed. It's not really an Exchange issue. It just so happens that ppl are bring up exchange since IMAP works in Outlook. Apple Mail is utilizing different system calls, again, which is why it works with Exchange. Finally, Outlook 2016 will work, however, most people using Outlook 2011 will *NOT* have that options since their company would have already had to upgrade to the latest version of Exchange.
Options to fix at this point:
* Downgrade to Yosemite (this is Microsoft's "workaround" and in my opinion, their response to a complete failure on their part to address this quickly)
* Upgrade to Outlook 2016 (it seems your company would need to upgrade to the latest Exchange backend as well)
* Migrate to Apple Mail (Works fine with the older Exchange Server - For those used to Exchange, this could be a slight learning issue. And you wouldn't have your local mailbox folders your created with Outlook, plus rules, plus categories, etc.)
* Get a VM app (VMFusion or Parallels and run Yosemite in there with Outlook 2011. I know this is almost laughable, but it would work)
* Wait for MS to fix this (Considering it is affecting businesses worldwide, maybe they will actually fix this faster. Unless this is their way to force Office 365 and the 2016 suite of apps.)
Anyone else have other options?
-EK