Sending email from ASP.Net 4 – C# sample code | Ponderings - Various Topical Thoughts by Brad Kingsley

Sending email from ASP.Net 4 – C# sample code

Posted by Brad Kingsley on January 12, 2012 Leave a comment (1) Go to comments

Below is sample code showing how to send email from ASP.Net 4 using C#. With this code I am assuming that the server already has a local SMTP service installed, so I use “localhost” to relay the email.

[UPDATE: Someone rightly pointed out that this example, if used 100% as-is, would create an open-relay situation and would quickly be abused by spammers. You should most certainly handle the From address as a variable defined and controlled by your code; and you should do something similar with the TO addresses, likely pulling them from a data source is this is a large mailing, or coding that to a variable also if this is just a feedback or contact form.]

Here is the SendMail.aspx page:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="SendMail.aspx.cs" Inherits="SendMail" %>

<head runat="server"><title>title></head>
<body>
    <form id="form1" runat="server">
        Message to: <asp:TextBox ID="txtTo" runat="server" /><br>
        Message from: <asp:TextBox ID="txtFrom" runat="server" /><br>
        Subject: <asp:TextBox ID="txtSubject" runat="server" /><br>
        Message Body:<br>
        <asp:TextBox ID="txtBody" runat="server" Height="171px" TextMode="MultiLine" Width="270px" /><br>
        <asp:Button ID="Btn_SendMail" runat="server" onclick="Btn_SendMail_Click" Text="Send Email" /><br>
        <asp:Label ID="Label1" runat="server" Text="Label">asp:Label>
    </form>
</body>
</html>

Here is the source code of the SendMail.aspx.cs page:

using System;
using System.Web.UI.WebControls;
using System.Net.Mail;
public partial class SendMail : System.Web.UI.Page
{
    protected void Btn_SendMail_Click(object sender, EventArgs e)
    {
        MailMessage mailObj = new MailMessage(
            txtFrom.Text, txtTo.Text, txtSubject.Text, txtBody.Text);
        SmtpClient SMTPServer = new SmtpClient("localhost");
        try
        {
           SMTPServer.Send(mailObj);
        }
            catch (Exception ex)
        {
            Label1.Text = ex.ToString();
        }
    }
}