Mariano has a nice post on sending emails with Collaboration Data Objects and Dexterity. If you don’t know what any of that means, don’t worry, you just haven’t achieved a high enough level of geekiness yet. It will come.
Emails, CDO and Dexterity
Archived post from 2009. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.