How to Change Your From Address in Outlook
If you normally send out emails from a mailbox other than your personal mailbox, you’ll notice that Sent items don’t go into the correct Sent items. To make sure they go to the right Sent items, you’ll need to specify the address you’re sending from.
Open a blank email in Outlook.
Click the Options tab and then click the … button to display additional options. From these options, click From.
The drop-down menu will display two options: your own email address an Other Email Address option. Click Other Email Address.
In the Send from Other Email Address window, click From… to select the address you want this message to be sent from.
In the Choose Sender window, select the Global Address List from the Address Book drop-down menu.
In the Search field, enter the email address you want to send from or search from the list.
The Send from Other Email Address window is now populated with the address you want to send from. Click OK to accept this address. You’ll see the new address in the From field of your blank email message.
Compose your message as you normally would and click Send.