ASP.NET联系人表单问题

Question

I'm setting this form up for a small business, so all the email gets sent directly to their mail server. I input the correct information and the mail successfully sends from the website, but it will never reach their mail server. Their mail server does give errors on the contact form saying 5.7.1 Message rejected as spam by Content Filtering. If it doesn't detect spam it will send, but still the server wont receive it.

Am I doing something wrong with the code or is the mail server rejecting it?

c# using System; using System.Net.Mail;

public partial class _Emailer : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack)
        {
            try
            {
                string output = "";

                MailMessage mail = new MailMessage();

                // Replace with your own host address
                string hostAddress = "xxx.xxx.xxx.xxx";

                // Replaces newlines with br
                string message = Request.Form["c_Message"].ToString();
                message = message.Replace(Environment.NewLine, "<br />");

                output = "<p>Name: " + Request.Form["c_Name"].ToString() + ".</p>";
                output += "<p>E-mail: " + Request.Form["c_Email"].ToString() + ".</p>";
                output += "<p>Phone: " + Request.Form["c_Phone"].ToString() + ".</p>";
                output += "<p>Message: " + message + ".</p>";

                mail.From = new MailAddress("xxxxxxx@xxxxxx.org");
                mail.To.Add("xxxxxxx@xxxxxxx.org");
                mail.Subject = "New e-mail.";
                mail.Body = output;

                mail.IsBodyHtml = true;
                SmtpClient smtp = new SmtpClient(hostAddress);
                smtp.EnableSsl = false;
                smtp.Send(mail);

                lblOutcome.Text = "E-mail sent successfully.";
            }

            catch (Exception err)
            {
                lblOutcome.Text = "There was an exception whilst sending the e-mail: " + err.ToString() + ".";
            }
        }  
    }
}

HTML

<asp:label id="lblOutcome" runat="server" />
        <form name="contact" method="post" id="cf">
            <div id="contactform">
                <p><img src="images/required_star.png" alt="Star" /> Required fields for contact form completion</p>
                <ol>
                    <li>
                        <label for="c_Name" class="required-star">Name:</label>
                        <input type="text" id="Text1" name="c_Name" placeholder="John Doe" class="required text" minlength="2" value="<% Response.Write(Request.Form["c_Name"]); %>" />
                    </li>
                    <li>
                        <label for="c_Email" class="required-star">Email:</label>
                        <input type="text" id="Text2" name="c_Email" class="required email text" placeholder="example@domain.com" value="<% Response.Write(Request.Form["c_Email"]); %>" />
                    </li>
                    <li>
                        <label for="c_Phone">Phone:</label>
                        <input type="text" id="Text3" name="c_Phone" class="phoneUS text" placeholder="ex. (555) 555-5555" value="<% Response.Write(Request.Form["c_Company"]); %>" />
                    </li>
                    <li>
                        <label for="c_Message" class="required-star">Message:</label>
                        <textarea id="Textarea1" name="c_Message" rows="6" cols="50" class="required" placeholder="..." minlength="2"><% Response.Write(Request.Form["c_Message"]); %></textarea>
                    </li>
                    <li class="buttons">
                        <input title="Submit" class="buttonBlue" value="Submit" type="submit" />
                        <input title="Clear the form" class="buttonBlue" value="Clear" type="reset" />
                    </li>
                </ol>
            </div>
        </form>

Answer 1

It looks like this is all down to the mail server filtering the emails. Perhaps contact the email host and explain your problem.

Answer 2

It may be treated as spam because of a lot of reasons. One of them is that from address does not match the host email was sent from. Eg you are sending email from pop3.yourhost.com and from field is my@name.com

Anyway it seems to have nothing to do with ASP.NET