This is what worked for several of my Macs with Outlook 2016 installed with OS X 10.11; please, read all of this, as the final step (#4) in this TL;DR list may be all that works for those reading this, but I found that my login Keychain was having issues with other 3rd-party apps, so I reset it. Outlook has been working flawlessly for me now for 6 days straight, 4-9 hours each day. I also now have Word/Excel working without issue as well.
Backstory: After experiencing crashing with Outlook (and Word/Excel/PowerPoint), and kernel panics, I used Little Snitch, Mail, and Outlook simultaneously to get the crashes and panics under control. I noticed that Outlook was polling each of the four servers in my Preferences at not-specified intervals - and Mail was reporting that flags were being changed at the time of the Outlook application crash or kernel panic - Little Snitch was showing that the polling had begun and, after a recovery, I noticed that mail marked by Outlook as “Read” was being reflected as “Read” in Mail at the time of the crash/panic.
What was troubling me was that the polling intervals were defined in the Account Preferences at 15 minutes, but Outlook was polling my 3 IMAP accounts and “dummy” Exchange Server account every 60 seconds, even with the dummy Exchange Server account disabled. Also, in Little Snitch’s Network Activity pane, I observed at least 6 additional Office-related Services working in the background and polling the account servers (I’m not going to get in to that here) - I've guessed that those additional services wanted access to the Keychain Access login credentials, and maybe that SIP was blocking that access? - Outlook was the only defined Item allowed access to the 4 accounts I’d set up in Outlook.
Resetting the Default login Keychain has solved issues with Mail, Chrome, and Opera on my Macs - the latter two use secure caches. I have noticed that issues with multiple versions of Mail accounts are resolved. I have uninstalled Little Snitch - that utility has been causing kernel panics on my main Mac. I don't have time to step others through Keychain Access - sorry, just to be up front about this. I won't take responsibility for borked Macs - resetting a Keychain and/or changing Access to Keychain Items aren't "new" fixes. I have submitted this workaround to MS, but haven't heard back from them (and, I'm not holding my breath...). Cheers!
- Open Keychain Access, record all of your passwords and accounts in the “login” list.
- Create a new login keychain, using Keychain Access.
- Open iCloud Preferences, log in to your iCloud account.
- Open Outlook, open its Preferences, add your primary account. Outlook will add an login Keychain item for that account. Quit Outlook. Double-click on the Keychain item just created by Outlook, navigate to the “Access Control” tab (the Outlook application should be the only application listed in this tab), and select “Allow all applications to access this item” - enter in your Account password, and Save Changes. Repeat the steps in this paragraph for each account.
Backstory: After experiencing crashing with Outlook (and Word/Excel/PowerPoint), and kernel panics, I used Little Snitch, Mail, and Outlook simultaneously to get the crashes and panics under control. I noticed that Outlook was polling each of the four servers in my Preferences at not-specified intervals - and Mail was reporting that flags were being changed at the time of the Outlook application crash or kernel panic - Little Snitch was showing that the polling had begun and, after a recovery, I noticed that mail marked by Outlook as “Read” was being reflected as “Read” in Mail at the time of the crash/panic.
What was troubling me was that the polling intervals were defined in the Account Preferences at 15 minutes, but Outlook was polling my 3 IMAP accounts and “dummy” Exchange Server account every 60 seconds, even with the dummy Exchange Server account disabled. Also, in Little Snitch’s Network Activity pane, I observed at least 6 additional Office-related Services working in the background and polling the account servers (I’m not going to get in to that here) - I've guessed that those additional services wanted access to the Keychain Access login credentials, and maybe that SIP was blocking that access? - Outlook was the only defined Item allowed access to the 4 accounts I’d set up in Outlook.
Resetting the Default login Keychain has solved issues with Mail, Chrome, and Opera on my Macs - the latter two use secure caches. I have noticed that issues with multiple versions of Mail accounts are resolved. I have uninstalled Little Snitch - that utility has been causing kernel panics on my main Mac. I don't have time to step others through Keychain Access - sorry, just to be up front about this. I won't take responsibility for borked Macs - resetting a Keychain and/or changing Access to Keychain Items aren't "new" fixes. I have submitted this workaround to MS, but haven't heard back from them (and, I'm not holding my breath...). Cheers!
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