Changing "From" field in an outbound e-mail

Changing "From" field in an outbound e-mail

I have numerous e-mail accounts and when I send an e-mail the From field auto-populates with my name and e-mail address. I've changed my account setting to make a secondary e-mail address my primary but the e-mail form still populates with the previous From address.
  1. Is there a way to set up a drop down so I can select which address populates the From field;
  2. Until (1) above is created, how can I change the address which is automatically populating the From field?
Thanks
TonyD - Marketing Wizard & Tony DeSimone National Accounts Manager for US Family Guide