Exchange Account Keeps Disappearing from Internet Accounts on macOS Mojave

I'd been having this problem, too, this week, and wound up chatting with Apple support about it. They said a new internal document today was suggesting the screen recording, and set up a call for later today after I'd made the recording.

But actually, once the support desk called me to connect me with engineering, they were able to help me fix it without escalating it further. They had me reset my keychain completely, then restart the computer. Once I did that, I was able to re-add the Exchange account, authenticate with third-party oAuth, and even turn iCloud Keychain back on. So far, seems to be working well.

Hopefully they'll have pushed a new update out before the next time I have to change my Exchange password, which I think is partly what triggered this whole glitch on my end. Good luck to anyone trying it for themselves, too!

I was finally able to get it working by performing two tasks:

Read this post - https://forums.macrumors.com/threads/exchange-account-keeps-deleting.2143129/#post-26970593

I deleted the OATH keys from keychain, added the Exchange(O365) account back but left Contacts unchecked, opened Contacts and saw a duplicate name for the account I was adding, removed it, and enabled the Contacts, from within the Contacts Preferences, for the newly added Exchange(O365) account, and finally it stayed and was not removed. Going on two days now.

Hope it works for you.

Here is what I did. So far, so good. The steps I followed were that I

1. turned off keychain in the iCloud preferences,
2. deleted all keychains with exchange in its name (those related to Exchange only),
3. deleted Exchange from both my Mac and my iPhone,
4. turned on keychain in the iCloud preferences,
5. added in my Exchange account on my mac using one email address associated with my account, then
6. added in my Exchange account on my iPhone using another email address associated with my account.

I have two email addresses associated with the same email account in Exchange (I send and receive from and to the same account using two different email addresses).

Like I said, this has worked for me so far.

@jeff.collier This partially works for me. If I do not select the 'Contacts' option when adding the Exchange account in Internet Accounts in the main system preferences, then the account adds fine and doesn't seem to disappear. I was also able to download all my mail and calendars also work, so far running 15 hours and the account hasn't deleted. However, I just tried to 'enable this account' in the Preferences/Accounts tab of the Contacts preferences and within a few seconds the account was deleted again.

So this does look to be an issue with the Contacts app somehow. I also did not reset my keychain and did not turn anything off in iCloud settings, the only thing I did was not select Contacts when adding the account.

Interestingly, in your Step 4 above you say it took you to the system preferences to tick the Contacts option, but when I do it the 'enable this account' option is just available right there in Contacts and it doesn't take me to system preferences.

Update: after Signing out of icloud; the exchange account stays put on both Macbooks.

Have you tried creating a new user account on your computer and setting up the exchange account from within that account? This would allow you to identify a configuration issue on your machine.

I found success with only one of your steps, like the Hope Diamond shimmering among of pile of mined ore. Having never reset Keychain or turned off the iCloud Keychain, I only:

1. Added back the Settings / Internet Account for Exchange but *omitted Contacts*
2. Opened Contacts
3. In Contacts, on the menu, selected Preferences / Accounts tab / Exchange item, and checked "Enable this account"
4. That took me back to Settings / Internet Accounts where I checked on the Contacts checkbox for Exchange

I can now confirm that I my O365 account has not been removed in well over an hour after configuring it with an O365 App password. This seems to be the correct temporary workaround until Apple resolves this issue permanently.

The workaround I have is to disable Keychain in iCloud. After doing so, I've been able to retain the exchange internet account.

Thanks, abrogio and meodavis. I was having the same problem so I turned off iCloud Keychain and restarted for good measure. I then added the Exchange account and so far it has been stable.

I have stumbled upon some more information about this.

While researching another issue, I found that I couldn't create app passwords in O365/Azure AD much like how you aren't allowed to. After disabling and then re-enabling MFA the app password creation issue was resolved and I could create an app password.

As a test I chose Configure Manually in the Exchange Internet Account wizard and used the app password. I was able to connect and the account has stuck around for over an hour now. I was also able to enable it on my Mac mini without issue.

Unfortunately this doesn't help you right now but perhaps it will be useful for getting Apple to figure out what is going wrong.

Did anyone get anywhere with support on this? I can confirm it is linked to iCloud keychain with exchange Modern Auth enabled. To be honest the first support rep didn’t know what oAuth was.

My support experience has been very poor so with Apple. Slow and asking quite silly questions even after console logs provide on the issue showing a timeout and exchange account being removed. Requested escalation and if this will be fixed in the next incremental update.

Got quite a few machines with this issue and so far the only creditable response I have received was, reinstall 10.14...

Appreciate the troubleshooting steps, but come on, handed the logs and walked them through the issue.