如何在ASP.NET中创建安全的“与我联系”表单？

Question

Please help,

I need to add a "Contact me" form to my website, most of tutorials almost use the same approach, but all of them don't work properly; instead of receiving the visitor message I receive a security problem warning like this:

Here is the code I used (outlook and gmail interact in the same way):

//this the event handler of the send button

protected void ButtonSend_Click(object sender, EventArgs e)

{
    if (Page.IsValid)
    {

    string fileName = Server.MapPath("~/App_Data/Message.txt");
    string mailBody = File.ReadAllText(fileName);

    mailBody = mailBody.Replace("##Name##", TextBoxName.Text);
    mailBody = mailBody.Replace("##Email##", TextBoxEmail.Text);
    mailBody = mailBody.Replace("##Subject##", TextBoxSubject.Text);
    mailBody = mailBody.Replace("##Body##", TextBoxBody.Text);
    MailMessage visitorMessage = new MailMessage();
    visitorMessage.Subject = "New Message: " + TextBoxSubject.Text;
    visitorMessage.Body = mailBody;

    visitorMessage.From = new MailAddress(TextBoxEmail.Text, TextBoxName.Text);
    visitorMessage.To.Add(new MailAddress("asdfg@outlook.com", "Mohamed"));
    visitorMessage.ReplyToList.Add(new MailAddress(TextBoxEmail.Text));
    SmtpClient mySmtpClient = new SmtpClient();
    mySmtpClient.Send(visitorMessage);
    LabelIRespond.Visible = true;

}
}

and for web.config:

  <system.net>
    <mailSettings>
      <smtp deliveryMethod="Network" from="Mohamed &lt;asdfg@outlook.com&gt;">
        <network host="Smtp.live.com" port="587" enableSsl="true" userName="asdfg@outlook.com" password="myOutlookPassword" />
      </smtp>
    </mailSettings>
  </system.net>

Please help me figure out what am I missing here, no one talk about this issue when they create such forms, I hope I find the solution here?

Thanks.

Answer 1

Most email services will fight you hard on allowing an application to log in and use it programmatically like this (in fact I think many have Terms of Use which prohibit this). This is how spammers would use a service to spam people if they could. Instead you need to find a service that will allow you to send emails via an API, or set up your own SMTP server.

I would suggest something like SendGrid: https://sendgrid.com/pricing , they have a free plan that includes 12,000 emails per month.