Add new From Address
-
Open a new email message.
-
Select the From button and then click Other Email Address.
-
Enter the new From email address or select the From button and search the Global Catalog for the address. 
Note: If you have more than one account added to Outlook, you will see a dialog that also has a Send Using button. Make sure to set this to the account that has permission to 'Send As' or 'Send on Behalf of' for the From address that you are adding.
Remove a From Address
- Open a new email message.
- Select the From button.
- From the list of From addresses, select the X to remove the entry.
Note
You cannot remove addresses for accounts that have been added to Outlook. These accounts will be at the top of the list and will not have a X next to them.
Additional Microsoft resources