[Exim] Help writing simple smtp sender

Folks,

At work I'm using VB.NET to write a class that can send a mail message
to an SMTP server, and do it properly. The reason is because I'm
learning VB and most of the alternatives cost money, and/or didn't have
the flexibility I wanted (e.g. logging the transaction). Note I'm not
asking here for info about VB, just about SMTP "clients".

I know a reasonable amount about SMTP, and I'm not going to get
esoteric, but I did wonder if there are any 'tips' any of you have,
particularly in what to avoid or ways to approach the task.

Regards,

Ruth