…How To…

 There are many instances when you will find it necessary to have to “attach” an exchange mailbox to an active directory account. One of the most common reasons is someones deleted the active directory account by mistake but sometimes if you are having trouble with one AD account that cannot be attributed to anything else it could be corrupt and so deleting and recreating said account is a rather drastic but quick way of sorting the issue out. Even if you create the account with the same name however the SID (Secure Identifier) will be different so it will be seen as a totally new account and you will then have to “reconnect” the microsoft exchange mailbox to it. In this article I explain exactly how to do this.
First of all you need to ensure you have your Exchange server setup correctly so if you delete the AD account the mailbox doesn’t disappear a bit sharpish as well. This would mean a tape restore and be alot more difficult.
To check this out open up Exchange System Manager, expand First Storage Group/Servers, right click the relevant mailbox store, select properties and then click on the limits tab as below:

As you can see our Exchange mailboxes are kept for 30 days before being deleted. (Also our deleted items are kept for 30 days but recovering them is another blog)
Now that we’re sure we’re safe to proceed (Although of course we have a tape backup as well) we can go ahead and delete the Active Directory account we want to recreate. Simply open up Active Directory Users and Computers, right click the relevant account and select delete. You will be prompted as below to Mark each selected Exchange Mailbox for deletion to which you say “Yes.”

The Active Directory account has now gone (Subject to the change being replicated throughout your forest) and you can go ahead and create a new account with the same name and settings. This is a simple matter of right clicking in the relevant OU and selecting New User. Create the account as you would a new user but be sure to remove the tick from create an exchange mailbox as below.

Now you have your Active Directory account recreated you need to associate or reconnect the original exchange mailbox with it. Open up Exchange System Manager, servers, find the relevant mailbox store, right click the mailboxes folder and select run cleanup agent. Once this has ran you will find that a red cross has appeared by the mailbox you marked for deletion earlier.

From within the Mailboxes folder as above simply right click the mailbox and select reconnect. It will then pop up asking for the Active Directory account you wish to connect to, fill in the name of the newly created account and it’s job done!

This article describes how to delete and restore an active directory account and associate an existing exchange mailbox with it.