Setting e-mail composing options
E-mail composing options include defining how new e-mail messages will look, setting default options for priority and requesting a return receipt; setting auto-fill name suggestion; selecting a default signature text; and setting e-mail addressing and name resolution options.
To set e-mail composing options
From the Tools menu, click Preferences, and then click the E-mail tab.
Click the Composing Options button.
Select options as needed. For field definitions, press F1.
Click OK.