One other thought on this train, would be to use Blat, to communicate with your smtp server. using blat, you can indentify your sent from - and reply to addresses all in one command line.
For automating of sending reports I use it, and the username would be say.
autoReportsys@mydomain.com etc. and that username does not actually exist.
Blat can be found at.
http://gepasi.dbs.aber.ac.uk/softw/Blat.htmlBob Lee
In the beginning, there was a command prompt, and all was well.
