I'm trying to determine if it's possible in Outlook(2010 specifically) to select the from address on a per-message basis if the user has multiple valid SMTP addresses on their Exchange mailbox. This is one of those things that is apparently un-googleable. For bonus points, it would be awesome if you could set the default from address per-contact.
Outlook – Set ‘From’ address in Outlook on a per-message basis
microsoft-outlookmicrosoft-outlook-2010
Best Answer
In the message window, switch to the Options tab, then enable "From". This will add a "From" input above the "To" line. You can put any mailbox for which you have Send As permission.
(Picture is from this guide)