Delphi

It can be so easy to have your application pop up an email window.
Assuming that an a mail reader is installed.

Uses ShellAPI;

ShellExecute(0,'open','mailto:DePaasHaas@DePaasHaas.com?subject=nice job', NIL, NIL, SW_SHOWNORMAL);

You must have the component TNMSMTP from FastNet tools. This component is included in Delphi 4-5 Professional and Enterprise

procedure TForm1.Button1Click(Sender:Object);
Begin
NMSMTP1.Host := 'mail.host.com';
NMSMTP1.UserID:= 'username';
NMSMTP1.Connect;
NMSMTP1.PostMessage.FromAddress:='webmaster@swissdelphicenter.ch';
NMSMTP1.PostMessage.ToAddress.Text := 'user@host.com';
NMSMTP1.PostMessage.Body.Text := 'This is the message';
NMSMTP1.PostMessage.Subject:='Mailsubject;
NMSMTP1.SendMail;
showmessage('Mail sent !');
end;