This article has the instructions on adding a second mailbox to your existing Exchange profile in Outlook. This way you will be able to access both mailboxes at the same time and run them both in Cached Mode.
Note: The other way to add an additional mailbox is to enable Full Access permissions for it and open it in your Outlook. Read the Knowledge Base article on How Do I Add Someone Else's Mailbox To My Exchange Outlook Profile?.
Adding a mailbox to your profile in Outlook:
- Close Outlook.
- Go to your Outlook mail settings from Start > Control Panel > Mail > Show Profiles.
If you cannot find the Mail icon in Control Panel, you can use search box.
If you still don't see Mail, open Run dialog box. To do this, press the Windows Key + R.
Type in Outlook.exe /manageprofiles and hit Enter.
- Double-click on your Exchange profile and then click Email Accounts.
- Click New:
- Then follow the instructions on How To Connect Mail Client to My Mailbox.
- Start your Outlook and enter the credentials for the additional Mailbox. When Outlook starts you will see it below your primary email account.
- If you want to have Outlook save your password, read the Knowledge Base article on How do I save my Outlook Password? for more information.
- You can set this email account as the Default one in Outlook > File > Info > Account Settings > Account Settings.
Highlight the account and hit Set as Default button.
Now, when you compose a new email, this email account appear in From field by default.