I have an email account on a customer's Exchange server and I need to ensure that I reply using that account to email traveling over that server. I don't want it to be my default account for normal email. Essentially, I want to say, "When replying to mail in Outlook Folder 'foo', use account 'lobrien@foo.com'." Is there a way to implement such a rule in Outlook or do I need to install VSTO and write some kind of Outlook extension?