Exchange account disappears in Mail after install of Mojave

There is a workaround that has worked for me until they actually fix the issue. Go into your iCloud account and uncheck Keychain. Not sure what the link is between Keychain and this issue but turning it off has allowed my Exchange account to stay active.

Thanks, Johan. I just found a few more suggestions on MacRumors: https://forums.macrumors.com/threads/exchange-account-keeps-deleting.2143129/

My Exchange account has stayed visible and apparentlyh stable for a record 10 minutes after doing the following:

1) When setting up the account check only Mail and Calendar. Instructions for adding Contact synching later are detailed on the page

2) The method for disabling keychains described below turned up a couple of things that hadn't showed up before when I just typed "outlook" or "exchange" in the search window. What came up didn't match the result in bold below, but I deleted it anyhow, and so far so good:

• Open Keychain Access (spotlight search is fastest)
• On the left-hand side, chose All Items
• In the Keychain Access search bar in the upper right, search for exchange
• In the results below, select all items that have com.apple.account.Exchange.oath-### and Delete them
• Quit Keychain Access and go Preferences --> Internet Accounts and re-add the Exchange accounts

Fingers crossed!

I think I may have found a solution online that actually worked.

1. Login to https://outlook.office.com/mail/inbox
2. Click on your initials at the top right corner of the screen and click on my account
3. Click on manage security and privacy
4. Click on Additional security verification
5. Click on Create and manage app passwords
6. Create a new app specific password for Apple and copy the password
7. Then create a new exchange account and click on configure manually and enter that password in.

This seemed to work for me and everything is now stable.

I have exactly the same issue, although it didn't materialise until a few days after installing Mojave. I think the problem started when I tried to add or move an Exchange inbox sub-folder in Mail.

Exchange account simply disappears. No error messages, it just goes. I can re-add, settings are accepted, inbox sub-folders appear, emails appear to start downloading but after a short period (seconds or a minute or two, it varies) the inbox dissappears along with the Exchange listing in 'Internet Accounts'. Other email accounts (iCloud, Yahoo) are fine in Mail and Exchange account is fine in Outlook. All is well on iOS devices.

It's not just the email element, it's the whole Exchange account as Calendar and Contact entries disappear too.

I've tried rebuilding the mailbox and manually deleting all cached messages but it makes no difference.

MacBook Pro Retina, mid-2015; Mojave (10.14).

I have the same issue - brand new 2018 MacBook Pro. Came with High Sierra, immediately upgraded to Mojave...then went to add an Exchange account (Office365) to Mail and it fails - same behavior. Adds Ok and begins to sync but after a few minutes, just disappears.... Do not have the issue on an older 2015 MacBook, however. Also upgraded to Mojave there, but the exchange account was already present ahead of time...

Exactly the same problem here too. I have tried to re-add the exchange account, already ~12 times, but every time it just disappears from the list of accounts. One time, I deactivated calendar, reminders, contacts, etc, and just kept mail checked during the initial setup, which resulted in the account last for a couple of days, but then it disappeared again. Serious issue. I have started to use Outlook, since this is a serious interruption.

After two days of trying various remedies, while working with Outlook for email (not pleasant), I think/hope I've got my Exchange account stable in Mail (and Calendar and Contacts).

As per my previous post, I rebuilt the inbox, removed accounts completely, tried just email (not calendar, contacts), tried just calendar (not mail, contacts)...all to no avail. I read a few posts in other forums suggesting deleting caches and/or specific control files (e.g. EnvelopeIndex-shm) in the mail system folder, but that didn't work. So I decided to throw caution to the wind and:

-removed ALL accounts from 'Internet Accounts' (I had iCloud, Yahoo and another, functioning Exchange account)

-made a backup of everything in Macintosh HD⁩ ▸ ⁨Users⁩ ▸ ⁨user_name ▸ ⁨Library⁩ ▸ ⁨Mail⁩ ▸ ⁨V6⁩

-deleted everything in Macintosh HD⁩ ▸ ⁨Users⁩ ▸ ⁨user_name ▸ ⁨Library⁩ ▸ ⁨Mail⁩ ▸ ⁨V6⁩

-popped "VIPs.plist" back in the MailData folder (Macintosh HD⁩ ▸ ⁨Users⁩ ▸ ⁨user_name ▸ ⁨Library⁩ ▸ ⁨Mail⁩ ▸ ⁨V6⁩ ▸ ⁨MailData)

Once the inboxes rebuilt themselves I was back where I was a few days earlier–VIPs, flags, etc. all intact. And so far, 48 hours later, I still have Exchange functioning in Mail.

I'm sure there's a more elegant and less heavy-handed way to achieve this but in the absence of such a method it might be worth doing what I did.

If there are any (negative) developments I'll be sure to post.

I had no issues, but after re-adding the Office 365 account to make use of Multi-factor authentication, this issue started immediately.

After multiple tries to add the account, I resorted to first removing the iCloud account. That seemed to work, the Office 365 account was not removed for at least 15 minutes. But sadly, after adding the iCloud account again, the Office 365 account almost immediately disappeared.

I have exactly the same issue. It did not start with Mojave, but with Mojave 10.14.1.

It appears to be related to re-establishing an Exchange account. IT moved the exchange server and my account on Monday. When I re-established the account that afternoon this behavior started.

It occurs on a 2016 MBP 15" and a MacPro 5,1.

When the account disappears from one, it appears to be deleted from the other.

This does not seem to effect IOS connections to the exchange.

I have tried only having the mail option. No difference.

Once an exchange account is setup, it works for a few minutes to an hour, then requests a login. When you login the account disappears.

Essentially Exchange has become unusable. I am looking for any suggestions.

Unfortunately none of the suggested fixes work for me. It started after I installed Mojave and had to recreate my Exchange account. The behavior is exactly as describe. I can create the account and log in, mail download starts but shortly after the accounts disappears. This occurs whether I create the account in calendar or mail, and whether I start mail in safe mode or not. In safe mode and with keychain disabled the account lasts a little longer but eventually disappears -- a few minutes to a few hours later. This is my work account so I need a fix as soon as possible. Any other ideas?

I too have been having this very annoying issue with the 2 machines I updated to Mojave. If you haven't already solved this problem, I saw a solution and so far (10 minutes) my account has remained on my computer.

The solution: go to your iCloud account and uncheck keychain. The iCloud account was listed under mail accounts and so it was easy to find and seems to be an easy fix. I am going to keep it unchecked on one computer and checked on the other to see if this is really the fix (scientist by nature). Good luck.

I had this problem with an Exchange account used for Calendar. I appear to have got it working again by quitting calendar, deleting Exchange and Office365 related items from Keychain, and adding the Exchange account from System Preferences -> Internet Accounts. The account didn't disappear after 60 seconds and after re-launching Calendar things appear to be back to normal (Exchange data has synced).

Yeah, I tried the same today for the company 365 account, didn't work. Same story, after a few minutes the account disappears. I use all the apps, not just calendar.

This is getting silly, has anyone bothered to submit a bug report?

For me, this issue seems to be resolved with macOS 10.14.2. I had the problem with 10.14.1, and did the workaround of disabling iCloud Keychain, which allowed the exchange account to stay. I tried reenabling iCloud Keychain with 10.14.1, but that would cause the Exchange account to disappear. After updating to 10.14.2, I once again enabled iCloud Keychain, and the Exchange account is still alive, 18 hours later.

I am on 10.14.2 and I am having this issue right now. It is exactly as everyone stated. It was stable until I removed my Office365 account from from one of my macs, i also have an iCloud account on my macs as well. But 10.14.2 hasn't solved it. I issue i am having is that it works for a short period of time, actually a little more specific as soon as i tried sending an outbound email, (Mac Mail app on my desktop) it remained in my outbox. When i checked the outbound server for my Outlook365 account had disappeared and then shortly thereafter the accounts uninstalled across all my desktop devices (not my mobile ones). I finally had to re-instal Outlook on my Desktop for now. IOS on iPhone 10 is working fine.