Converting a Mail User to a Remote User Mailbox

I have an client with an existing Office 365 implementation and a separate on-premises Exchange organization. As part of linking these two together into hybrid mode, the local AD account became a Mail User.

A Mail User is a local AD account with an external SMTP address configured. This allows the user to have an email address in the GAL, but is not a local Exchange mailbox.

To move mailboxes, this Mail User needs to be configured as a Remote User Mailbox. A Remote User Mailbox also has a proper remote routing address property configured.

I couldn't find any documentation on performing this process. However, I did find a script that indicates it fixes up user accounts when a mailbox move to Office 365 does not complete properly. I used this script to identify the changes that needed to be made.

The script is here:
The changes that need to be made are:
  1. Configure the user attribute targetaddress to contain the remote routing address for the mailbox. This should be in the format of userid@domain.mail.onmicrosoft.com. In my case it would have been testmailbox@byronwright.mail.onmicrosoft.com.
  2. Set the msExchRemoteRecipientType attribute for the user account to equal 4.
  3. Set the msExchRecipientDisplayType attribute for the user account to equal -2147483642. (yes, this is a negative value)
  4. Set the msExchRecipientTypeDetails attribute for the user account to equal 2147483648.
Those steps changed the Mail User to a Remote User Mailbox. However, I was still unable to move the mailbox from Office 365 to the on-premises Exchange. This was due to the ExchangeGUID attribute not being set properly on the local user account. To fix this, I performed the following:
  1. In Office 365: get-mailbox testmailbox | fl ExchangeGUID
  2. In on-premises Exchange: set-remotemailbox testmailbox -ExchangeGUID 12345678-1234-1234-1234-123456789abc (note GUID is from step 1)
After setting the ExchangeGUID moves to the on-premises Exchange worked properly.

UPDATE: See a similar procedure for room mailboxes at: http://byronwright.blogspot.ca/2014/06/putting-office-365-room-mailboxes-in.html 

UPDATE: While the above seemed like a good procedure at the time. I've since become aware that you can use Enable-RemoteMailbox in this same scenario to fix up the local mail users to remote user mailboxes. For a script to do it on a whole OU, see here: http://byronwright.blogspot.ca/2014/10/script-to-resolve-error-when-running.html

Comments

  1. AnonymousMay 1, 2015 at 2:41 PM

    Thank you. This was very helpful!

    ReplyDelete
  2. BenNovember 7, 2016 at 7:52 AM

    Thanks for the helpful article.

    ReplyDelete
  3. AnonymousAugust 23, 2017 at 10:24 PM

    Thanks for the info. Be aware that if you are in hybrid mode then the enable-remotemailbox must be used along with the set-remotemailbox with the ExchangeGUId of the cloud mailbox being the parameter

    ReplyDelete
  4. AnonymousApril 3, 2018 at 2:34 AM

    Thanks man, doing steps A1-A4 also solved an issue for me where it was not possible to send a user mails from an external domain.

    ReplyDelete

Post a Comment

Popular posts from this blog

Remove OEMDRV Drive from Dell Server

I recently installed a Dell Server by using the Lifecycle Controller. This system uses a wizard to help with the installation of the operating system. In this case, I was installing Windows Server 2008 R2 to replace an existing Exchange 2010 server. As part of the installation, an OEMDRV USB drive is created by the Lifecycle Controller that contains the drivers used during OS installation. OS installation went well, but I ran into an issue afterwards. The OEMDRV drive was using E:, which I needed for my Exchange data. When you go into computer management, OEMDRV shows as a removable drive. However, you cannot change the drive letter or eject OEMDRV. By default the Lifecycle controller removes this drive after 18 hours, but I didn't want to wait that long. To force OEMDRV to be removed earlier, restart the server and press F10 to enter the Lifecycle Controller configuration. Then exit the Lifecycle Controller and reboot again. You don't need to make any changes in the configurat...
Read more

Expired Microsoft Exchange Server Auth Certificate

Image
When you install your first Exchange Server 2013 or Exchange Server 2016 server, a certificate with the friendly name Microsoft Exchange Server Auth Certificate is created. This certificate is self-signed and used for OAuth authentication between applications such as Exchange Server and SharePoint. However, it is also used for hybrid deployments between on-premises Exchange Server and Exchange Online. This certificate is unique because it is installed on all of your Exchange servers. The subject for the certificate is "CN=Microsoft Exchange Server Auth Certificate" and does not contain any SAN names with references to specific servers. It also has a 5-year lifetime. Which is just long enough for everyone to forget about it. I suspect that this certificate is due to expire in many organizations soon. Today I got a call from an organization with the following symptoms: Outlook clients were slow to start Outlook clients were not displaying the user's calendar Outlook clients...
Read more

Stop SBS from Shutting Down

We are currently migrating a client from SBS 2003 to SBS 2008. We've joined the new computer to the the domain, and run DCpromo on the SBS 2003 computer to remove the DC status. However, after seven days, SBS 2003 will start giving an error stating that it needs to be a DC and will shut down every 60 minutes ( http://support.microsoft.com/kb/555087 )! We need another few days to work on the migration. The Microsoft recommended solution for this is to insert disc 1, run setup, and remove the SBS 2003 component. This will leave a plain Win 2003 server without the shutdown issue. However, when I attempted to do this, setup errored out indicating that I was trying to upgrade to an older version which was not possible. Removing service packs may have worked, but here is a faster work around taken from a guy named Alan ( http://social.microsoft.com/Forums/en-US/whssoftware/thread/af4fc3b4-bb50-4c5e-b09a-72ef2c3ac687 ) I've found a slightly more elegant solution to this problem rather...
Read more