Creating the Messaging service account

Procedure

Open Exchange Management Console and select Recipient Configuration.
In the Action pane, click New Mailbox.
For Mailbox Type, choose User Mailbox.
For User Type, choose New User.
Complete the User Information fields.
Use a site or location specific naming convention for the account name. For example, AuraMsgSvcAcctSiteA.
Complete the Mailbox Settings fields as needed, and click Next.
Complete the Archive Settings fields as needed, and click Next.
On the Summary screen, click New and verify that the system successfully created the mailbox.
Open Active Directory Users and Computers.
Locate your newly created service account, and right-click and select properties.
Click the Account tab and ensure that the Password never expires check box is selected.
In the Member Of tab, ensure your service account is not a member of any administrative group.