How to eMail using c#

using System;

using System.Net.Mail;

namespace Tools

{

    public class eMail

    {

        public class SMTP

        {

            private string _userName = "";

            private string _password = "";

            private string _smtpserver = "";

            private string _from = "";

            private string _subject = "";

            private string _body = "";

            MailMessage _smtp_mail = new MailMessage();

            public string SMTPServer

            {

                set { _smtpserver = value.Trim(); }

            }

            public string From

            {

                set { _from = value.Trim(); }

            }

            public string Body

            {

                set { _body = value.Trim(); }

            }

            public string Subject

            {

                set { _subject = value.Trim(); }

            }

            public SMTP()

            {

                this._userName = "";

                this._password = "";

                this._smtpserver = "localhost";

            }

            public SMTP(string user, string pass, string smtp_server)

            {

                this._userName = user;

                this._password = pass;

                this._smtpserver = smtp_server;

                MailMessage _mail = new MailMessage();

            }

            public void Credentials(string user, string pass)

            {

                this._userName = user;

                this._password = pass;

            }

            public void AddToRecipient(string recipient)

            {

                _smtp_mail.To.Add(new MailAddress(recipient));

            }

            public void AddBccRecipient(string recipient)

            {

                _smtp_mail.Bcc.Add(new MailAddress(recipient));

            }

            public void AddCcRecipient(string recipient)

            {

                _smtp_mail.CC.Add(new MailAddress(recipient));

            }

            public void Send()

            {

                _send();

            }

            public void Send(string From, string To, string Subject, string Body)

            {

                _smtp_mail.To.Add(new MailAddress(To));

                this._from = From;

                this._subject = Subject;

                this._body = Body;

                _send();

            }

            private void _send()

            {

                //set the addresses

                _smtp_mail.From = new MailAddress(this._from);

                //set the content

                _smtp_mail.Subject = this._subject;

                _smtp_mail.Body = this._body;

                //send the message

                SmtpClient smtp = new SmtpClient(this._smtpserver);

                if (!(_userName.Trim() == "" && _password.Trim() == ""))

                {

                    smtp.Credentials = new System.Net.NetworkCredential(_userName, _password);

                }

                try

                {

                    smtp.Send(_smtp_mail);

                }

                catch (Exception e)

                {

                    throw e;

                }

            }

        }

    }

}