Q: If you manage multiple mailboxes, how do you change the from in outlook?

A: To send email, reply, or forward email as a different address (i.e., somebody@myaddress.com) vs. yourself,

Click on the From button.
Click on Other Email Address.
In the From Box, type somebody@myaddress.com Click OK.

You should see the From address has changed (temporarily) and somebody@myaddress.com has now been added as an option in your From list.