office 365 thinks the mailbox is local, local exchange says its on office365

[chazzy2501]

We've had a member of staff leave us and come back. Originally she was on the o365 system, after leaving her active directory account was moved to disabled (and disabled) this takes it out of the o365 scope (thus deleting the account from o365). a year later she's come back, we had her in the disabled accounts (in ad) so just put her back with her old password. At this point office 365 should have made a new account.

 

Now I'm unsure what her email status would be. I thought i'yd just make a new mailbox but it seems to think there is a local exchange account that need migrating. The local exchange server still thinks there is a o365 mailbox. How should I proceed? (and what should I do in the future)

[chaplic]

After a year the account will be gone from O365 for sure. However, I'm guessing the relevant AD fields of the user say 'this guys got a remote mailbox'. If you look at AD attributes for the user, I suspect msExchRemoteRecipientType is set to 4

In Exchange on premise, use powershell to disable the remote mailbox from the user - this will scrub the relevant AD fields. Wait a Azure AD sync cycle or two, and if licensed o365 will create the mailbox.

 

https://docs.microsoft.com/en-us/powershell/module/exchange/federation-and-hybrid/disable-remotemailbox?view=exchange-ps

Edited January 6, 2019 by chaplic

[Netwacky87]

This is whats called (well I call it) a split brain in a hybrid exchange situation - Sounds like what you have?

 

So you have to force remove from Office 365, and then move the mailbox from Exchange Local to office 365. I have the commands somewhere i'll post them when I find them.

[Netwacky87]

These are my notes:

 

1. Force a DirSync. This should force a deletion of the account in Office 365 (Azure AD)

a. Move the AD account into an OU which is not being synchronized with Office 365 (Azure AD).

b. Start-ADSyncSyncCycle -PolicyType Delta (Delta Sync)

c. Start-ADSyncSyncCycle -PolicyType Initial (Full Sync)

2. Check that the account has been deleted from Azure AD, if it hasn’t, force DirSync again. Do this until AD account is removed from Azure AD

3. Use Azure AD remote PowerShell to remove the account from the user recycle bin.

$UserCredential = Get-Credential

Connect-MsolService -Credential $UserCredential

Remove-MsolUser -UserPrincipalName ‘upn’ -RemoveFromRecycleBin –force *THIS WILL DELETE THE USER, FILES and EMAILS FROM OFFICE 365!!(!)*

4. Check through the O365 admin UI portal, that the account has gone from the recycle bin

5. Move the AD account back into an OU which is being synchronized with Office 365 (Azure AD)

6. Force DirSync. This will re-provision the account into Office 365 (Azure AD)

7. Check that msExchRecipientDisplayType is now what it should be e.g. “-2147481594”.

8. Try move mailbox again