You want to open another user’s mailbox in your desktop Outlook.
This is done in Outlook.
- First Follow the steps found on how to Grant Send-As permissions in MyExchange
- Open up outlook and Click File and choose Account Settings.
- Once in Account settings choose the Change option under the Email tab.
- Click the “More Settings” button, and then click the Advanced tab.
5. Click Add, and then type the mailbox name of the person whose mailbox you want to add.
6. All done! The new email address will appear in outlook as a top-level folder.