The message object (of course) plays the central role in any (object oriented) e-mail library. The performance of the header and body implementations is crucial to the performance of all applications, and therefore there are various versions of them.

All the kinds of body implementations and all the kinds of header implementations provide the same methods, but for some reason or the other one may be preferred for performance reasons. Don't be afraid for this: these variations are hidden for almost everyone.

The body decoded method is very important. Read more about that in other documents. There is not enough time in this presentation to explain it all.