Exchange Account disappears in Mail

Open Keychain Access in Utilities, enter the part after the @ sign in the search bar, hit enter

You may have multiple entries.  You can edit them or delete them & start over.

The release notes for MacOS 10.14.4 say the update fixes this bug--hurray!

https://support.apple.com/en-us/HT209149

I think I might have found a solution...

1) Remove your Exchange Account.

2) Open up Keychain Access (Spotlight > Keychain Access).

3) Search for 'exchange', and then select and delete all 'exchange' Entries (see screenshot below)

4) Re-add your Exchange Account.

5) Seems to be working so far for me.

I have managed to make the Exchange account not to disappear by adding it only for E-mail and Calendar, leaving all other services, especially Contacts, unchecked. AND then making sure the same setup is used on ALL machines connected to the Apple ID, e.g. by unchecking Contacts etc. on all my other phones and computers.

Did that a week ago, and the account is still here today.

Disabling contact sync didn’t relly hep for me if you add the account on a second computer which also has icloud keychain sync enabled.

i disabled the icloud keychain sync and removed it from both machines.

now both accounts stay on both machines

Hey everyone,

I noticed that it was disappearing after it had finished downloading the headers for the email. I tried re-adding just the mail (no contacts, notes etc) and it worked. it didn't disappear.

I think there's obviously a bug somewhere in Mojave. I'm sure there'll be a fix soon enough. In the meantime, just add only the mail.

Hope it helps.

Alex

I did just discover what appears so far to be a fix. I have several email "aliases" at my institution. I don't know enough about Exchange/Windows/Office365 to tell you exactly how these various email "aliases" are set up on the server side; all I can say is that from my point of view as a user mail sent to any of them ends up in the same Exchange inbox.

Anyway, I tried setting up the Exchange account in OS X Mail using the automatic option, but entering a different (and I think older) email alias as my Exchange email address. When I did that, the account got created and has persisted so far for several hours without disappearing.

As a curious sidelight, I did download the Spark email client from the app store and set up my Exchange email account in that application using it's account "wizard". In Spark, the Exchange account got created and stably persisted, even though I used the very email alias that had failed to stably function in OS X Mail.

Go figure. I agree Apple needs to figure this one out.

Don't know yet if this is a good solution yet, but I was any able to make it work without selecting Contact in the choices of programs that will sync with Exchange. I also had the exact same issue as everyone here, where the account disappear automatically after 30 sec.

Same here current Mojave build (Exchange Online, O365, MultiFactorAuthentication)...

Problem startet for me like this:

1. mail suddenly didn't accept my password
2. i removed the account > macOS asks "do you want to remove from all computers?" > YES
3. i guess this is the issue and the command to remove the account from all computers is stuck in some kind of iCloud sync loop
4. can't add my O365 exchange account anymore because it disappears
5. deleted all keychain items related to exchange, also items just containing my o365 e-mail address and type "application password"
6. still not working
7. disabled iCloud keychain sync > "do you want to keep or remove from this mac" > remove from mac
8. added account > seems to work
9. re-anabled icloud keychain sync
10. >>>>>>>>>>> account disappears again!
11. i also sometimes saw a message that the mailbox DB is in use and need a rebuild

Same for me. Only by disabling iCloud Keychain that I could make this work.

Try to add without contacts sync enabled, works for me...

I have the same issue when setting up an exchange account using the "automatic" feature. However, configuring manually seems to allow the account to persist.

Solved for me:

1. removed the account and left it without for the last 3 days
2. added it today and it stayed there for the last 20minutes... we'll see ;)

I did what the message suggests: reboot/logout. Now mail starts and the account is there... Will let you know if it disappears again...