Exchange account disappears in Mail after install of Mojave

Ooops! Apparently I spoke too soon. Once again the Microsoft Outlook Exchange account has disappeared. I have removed all Outlook and exchange addresses from Keychain and unchecked Keychain in Preferences>iCloud, closed Mail and re-started the computer. Any updates for solving this issue?

Any more updates on this? Still no luck for me and experiencing the same as everyone else. So freaking annoying as this is a work account for me as well and, man, do I not want to have to use Outlook.

Just letting you know that the fix from the website link I posted on January 19th solved the issue for me - and it's been stable for 4 days now. I feel your pain, though. I was also dreading having to use Outlook for work. Maybe poke around a little more on that linked website for other options? Good luck.

Thanks for the reply. Tried everything from the linked website and still vanishing into thin air. Only thing that has worked is unchecking Keychain in Icloud and that is such a crappy work around. So frustrating.......

Thanks! This eventually worked - I kept having the problem until I uninstalled the problematic exchange account from all my linked devices (phone, ipad, laptop). After that, I removed the "exchange" keys from keychain. Then, I reinstalled the exchange account on all the devices. No problems since.

I had this problem too on Mojave and finally managed to fix it. Like others the Exchange account would mysteriously auto-delete after a few minutes of being created. This only happened when iCloud Keychain syncing was ON AND Contacts syncing with Exchange was on.

I tried lots and lots and lots of things - all the above - and others like trashing half my Library folder! Tore my hair out. This is what finally seemed to work:

0) turned Keychain syncing off on the Mac in question

1) deleted/reset my login keychain and all files in Library/Keychain 

2) deleted everything I could in my System Keychain (except for airport passwords). 

3) deleted every 'certificate' I could in my System Keychain on all my Macs.

I think it might have been the last thing that did it, but when I turned keychain syncing back on, the problem went away,

My conclusion was I had some sort of poisonous certificate in my keychain.

Phew!

I disabled Keychain, and the problem was resolved, but that disables an important function, so I think a better workaround is to just unselect "contacts" when adding the account. Contact seems to be causing the bug. I can still select Mail and Calendar.

I have been told by my employer IT department that "Apple has indicated that this should be fixed in Mojave version 10.14.4.

Since this is currently only in Beta we have not been able to test it yet. 

Apple has not set a release date for that update at this time, but it looks to be soon"

With that being said, guesses on when 10.14.4 will move from beta to production? Or better yet, does anyone currently have the beta downloaded and use an exchange account with no issue?

I tried this and it seems to be working... very short term work around through as I need key chain to share updated password across all apple devices

anyone got an update on this?

Whenever I have an Exchange email account that gives me problems on macOS or iOS,

I just manually re-add the problematic account as an IMAP account instead, and that usually fixes the issue(s).

Does not solve the problem, you are basically using an legacy mail protocol and removing MFA (Modern Auth) from the account...

Yes it works, but very poor security.

This worked for me. I think is the easiest way until Apple fixes this bug.