Email Address Validation for ASP.NET

Question

What do you use to validate an email address on a ASP.NET form. I want to make sure that it contains no XSS exploits.

This is ASP.NET 1.1

Answer 1

Here is a basic email validator I just created based on Simon Johnson's idea. It just needs the extra functionality of DNS lookup being added if it is required.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.UI.WebControls;
using System.Text.RegularExpressions;
using System.Web.UI;

namespace CompanyName.Library.Web.Controls
{
    [ToolboxData("<{0}:EmailValidator runat=server>")]
    public class EmailValidator : BaseValidator
    {

        protected override bool EvaluateIsValid()
        {
            string val = this.GetControlValidationValue(this.ControlToValidate);
            string pattern = @"^[a-z][a-z|0-9|]*([_][a-z|0-9]+)*([.][a-z|0-9]+([_][a-z|0-9]+)*)?@[a-z][a-z|0-9|]*\.([a-z][a-z|0-9]*(\.[a-z][a-z|0-9]*)?)$";
            Match match = Regex.Match(val.Trim(), pattern, RegexOptions.IgnoreCase);

            if (match.Success)
                return true;
            else
                return false;
        }

    }
}

Update: Please don't use the original Regex. Seek out a newer more complete sample.