I use ASP.NET and C# with a project I am working on at the moment. The .NET Framework has an SmtpMail class built into it which works really well.
I wrote some code to send an e-mail when I get a PayPal IPN response and it took less than an hour to implement.
Code:
MailMessage message = new MailMessage();
message.From = from;
message.To = to;
message.Subject = subject;
message.Body = body;
message.BodyFormat = bodyFormat;
SmtpMail.SmtpServer = smtpServer;
SmtpMail.Send(message);
All you need to do is add your own information to the variables.
If anyone would like any further information about this or any other C# question, I'll try and answer it for you!
Cheers,
Ed