The Address Pane is shown below.

Addresses can be selected and moved to the From, To, Copy and Bcc fields using the mouse, hotkeys or context menu.
Address context menu
–Edit Address: edit the address.
–Delete, Cut, Copy: perform the corresponding operation on the address.
–Move to To: move the address to the To field.
–Move to Cc: move the address to the Cc field.
–Move to Bcc: move the address to the Bcc field.