Refer the below code.
protected void Button1_Click(object sender, EventArgs e)
{
string isim = string.Empty;
string soyisim = string.Empty;
string email = string.Empty;
string body = string.Empty;
OleDbConnection cnn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Server.MapPath(@"App_Data\MailDB.mdb"));
OleDbCommand bulten = new OleDbCommand("SELECT isim, soyisim, mail FROM Mailler", cnn);
if (cnn.State == ConnectionState.Closed)
{
cnn.Open();
}
OleDbDataAdapter bdr = new OleDbDataAdapter(bulten);
DataTable dt = new DataTable();
bdr.Fill(dt);
cnn.Close();
foreach (DataRow row in dt.Rows)
{
isim = row["isim"].ToString();
soyisim = row["soyisim"].ToString();
email = row["mail"].ToString();
body = string.Format("Mr/Mrs {0} {1},<br/><br/>{2}<br/><br/>", isim, soyisim, txtmesaj.Text);
SendEmail(email, txtkonu.Text, body);
}
lblmesaj.ForeColor = System.Drawing.Color.Green;
lblmesaj.Text = "E-Postalar Başarıyla Gönderildi";
}
private bool SendEmail(string recipient, string subject, string body)
{
MailMessage mm = new MailMessage("xxxx@xxxx.com", recipient);
mm.Subject = subject;
mm.Body = body;
mm.IsBodyHtml = true;
SmtpClient smtp = new SmtpClient();
smtp.Host = "smtp.gmail.com";
smtp.EnableSsl = true;
NetworkCredential NetworkCred = new NetworkCredential();
NetworkCred.UserName = "xxxx@xxxxx.com";
NetworkCred.Password = "password";
smtp.UseDefaultCredentials = true;
smtp.Credentials = NetworkCred;
smtp.Port = 587;
smtp.Send(mm);
return true;
}