Exchange Account Keeps Disappearing from Internet Accounts on macOS Mojave

That doesn't work for me. I'm having the same issue right now (I have two exchange accounts, and one of them keep disappearing). Have reseted keychain two times - no effect, account still disappearing.

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.

@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.

A quick update on this....received a prompt from system preferences saying Mail needed by exchange password, and after successfully re-authenticating the account disappeared from Internet Accounts within a few seconds, even with Contacts still disabled. So although it seems possible to add the account without enabling Contacts, when you hit the 30 days limit to re-authenticate then it looks like there is still a problem.

Has anybody who has managed to get their fix to work re-enabled Contacts AND gone through a re-authentication process, with the account still not deleted?

I had the same problem: an Exchange account that I added would not stay more than a few minutes within "Internet Accounts."

I found on a couple other forums the suggestion to add the account manually, which I did and everything seems to be working great!

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.

Did you find a solution? I'm running into the same thing.

I'm also having this issue. In an attempt to alleviate this issue, I've signed in using a O365 App password. Will report back with my status later.

I have the same issue. I have a Google Apps account configured just fine, but my work O365 account keeps randomly disappearing. Going to try to the app password method mentioned in this thread.

Yes, a few weeks ago on High Sierra I did the "Remove from All" step.

I did the same thing, however it didn't remove from my other devices. I wonder if somehow there is a flag set to "remove" and every time the account is added it's deleted?