Provides and Electronic Mail (Email) address.

EmailAddress.cs

using System.Text.RegularExpressions;

namespace System.Net.Mail
{
    /// <summary>
    /// Provides an Electronic Mail (Email) address.
    /// </summary>
    public sealed class EmailAddress
    {
        private const string EMAIL_PATTERN = @"([a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*)@((?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?)\.+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?)";

        public string LocalPart { get; private set; }

        public string DomainPart { get; private set; }

        public string FullAddress { get; private set; }

        public EmailAddress() { }

        public EmailAddress(string localPart, string domainPart)
        {
            if (string.IsNullOrWhiteSpace(localPart))
                throw new ArgumentNullException("localPart", "localPart is null.");
            if (string.IsNullOrWhiteSpace(domainPart))
                throw new ArgumentNullException("domainPart", "domainPart is null.");

            LocalPart = localPart;
            DomainPart = domainPart;
            FullAddress = string.Concat(localPart, '@', domainPart);
        }

        public static bool TryParse(string emailString, out EmailAddress result)
        {
            try
            {
                result = Parse(emailString);
                return true;
            }
            catch
            {
                result = null;
                return false;
            }
        }

        public static EmailAddress Parse(string emailString)
        {
            if (string.IsNullOrWhiteSpace(emailString))
                throw new ArgumentNullException("emailString", "emailString is null.");

            var match = Regex.Match(emailString, EMAIL_PATTERN);

            if (!match.Success) throw new FormatException("emailString is not a valid Email address.");

            return new EmailAddress(match.Groups[1].Value, match.Groups[2].Value);
        }

        public override bool Equals(object obj)
        {
            if (obj == null) return false;
            var other = (EmailAddress) obj;
            return FullAddress == other.FullAddress;
        }

        public override int GetHashCode()
        {
            return FullAddress.GetHashCode();
        }
    }
}