about programmatically sending emails by LotusNotes

Does any body has the experience programmatically sending emails by lotusnots from different sender email addresses?

I am coding using ASP.NET/C#, a web program. It requires no matter who login, an email should be sent automatically after certain operation.

I can only send emails from my machine using my password and mail file and server name.

But for others, how can I do it?

This problem has bothered me quite a while

Please help thanks,