How to retrieve e-mail account from acctive dirrectory

please advise how to retrieve user emal accounts from acctive dirrectory and assign it to the mailMsg.to property. public void send(string strMessage) { //System.Web.Mail.SmtpMail.SmtpServer = "mail.ionhealth-pa.com"; MailMessage mailMsg = new MailMessage(); mailMsg.From = "[email protected]"; mailMsg.To = "[email protected],[email protected],[email protected]"; mailMsg.Subject = "Try Out10"; mailMsg.Body = (strMessage); SmtpMail.Send(mailMsg); }