try this:
first, include this namespace:
using System.Net.Mail;
then create an Email function:
void Email(string receiversname)
{
MailMessage MyMailMessage = new MailMessage();
MyMailMessage.From = new MailAddress("youremail@gmail.com", "your title");
MyMailMessage.To.Add(eadd);
MyMailMessage.Subject = "your e-mail subject";
MyMailMessage.IsBodyHtml = true;
MyMailMessage.Body = "<body bgcolor=\"#F5F5F5\"><center><font face="\"Cambria\"">
<pre lang="text">Note you can add more MyMailMessage.body here for the content of the email
SmtpClient SMTPServer = new SmtpClient("smtp.gmail.com");
SMTPServer.Port = 587;
SMTPServer.Credentials = new System.Net.NetworkCredential("your email here", "your email's password");
SMTPServer.EnableSsl = true;
try
{
SMTPServer.Send(MyMailMessage);
}
catch (Exception ex)
{
ClientScript.RegisterStartupScript(this.GetType(), "myalert", "alert('" + ex.Message + "');", true);
}
now on your send button click event,
enter the following code:
receiversname= txtEmail.Text.ToString();
Email(receiversname);