First, you will need to start Microsoft Outlook Express. This will start Microsoft Outlook Express for the main account iden.y. Click on the File menu, then click on Iden.ies, then choose Add New Iden.y .To set up a separate iden.y in Outlook Express, do the following: Open up Outlook Express. Click on the File menu at the top. From the File menu Select Iden.ies > Add New Iden.y. The New Iden.y box appears, and looks like this:.