Validate email address in C#

In this blog, let's see how how to validate email address in C#. We can use C# Regex class and regular expressions to validate an email in C#. The following Regex is an example to validate an email address in C#.

Regex regex = new Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$")

If you're new to C# regular expression, check out C# Regex Examples

Here is a simple ASP.NET page that uses C# Regex to validate an email address.

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Email_validation._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox runat="server" ID="txtemail"></asp:TextBox><br />
<asp:Button runat="server" ID="Validate" Text="Validate Email id"
onclick="Validate_Click" />
<asp:Label ID="lbl_message" runat="server" Font-Bold="True"
ForeColor="#CC3300"></asp:Label>
</div>
</form>
</body>
</html>
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Text.RegularExpressions;
namespace Email_validation
{
public partial class _Default : System.Web.UI.Page
{
private void ValidateEmail()
{
string email = txtemail.Text;
Regex regex = new Regex(@"^([\w\.\-]+)@([\w\-]+)((\.(\w){2,3})+)$");
Match match = regex.Match(email);
if (match.Success)
lbl_message.Text=email + " is Valid Email Address";
else
lbl_message.Text = email + " is Invalid Email Address";
}
protected void Validate_Click(object sender, EventArgs e)
{
ValidateEmail();
}
}
}