Several mail applications and web mail services do not actually specify a font when composing and sending a message in HTML format. So although the sender thinks that he/she is sending a message in the Arial format, it actually arrives in Times New Roman on my computer.

This is of course because Outlook uses Times New Roman as the default font when none is specified.

Is there any way that I can change this default font to something different than 12pt Times New Roman? For instance, 10pt Arial?