create mail server

hello
i had a domain and some days a go i register a hosting from discount. it's really perfect.
NOW
i write a program (asp.net) that run in my iis (local) but i want to send mails from may mail address that i define in my hosting ([email protected]).
it means i have a form and lod some sender's address from may DB and i want to send them mails.
it's my config code

Code:

	<mailSettings>
            <smtp from="[email protected]">
                <network host="smtp.elmosanat.co.ir" userName="" password="" />
            </smtp>
		</mailSettings>

and my sendmail.aspx code

Code:

MailMessage mailMessage = new MailMessage();
        mailMessage.From = new MailAddress("[email protected]");
        mailMessage.To.Add("****@yahoo.com");
        mailMessage.Subject = Subject;
        mailMessage.Body = body;
        mailMessage.BodyEncoding = System.Text.Encoding.UTF8;
        SmtpClient smtp = new SmtpClient("Localhost"); 
        smtp.Send(mailMessage);

i know that if i load my program on my hosting mail my be send but i want to load it in my computer just use my domain SMTP server.
please guide me.