extract all email address from a text using c#

check this snippet

using System.IO;
using System.Text.RegularExpressions;
using System.Text;

class MailExtracter
{

    public static void ExtractEmails(string inFilePath, string outFilePath)
    {
        string data = File.ReadAllText(inFilePath); //read File 
        //instantiate with this pattern 
        Regex emailRegex = new Regex(@"\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*",
            RegexOptions.IgnoreCase);
        //find items that matches with our pattern
        MatchCollection emailMatches = emailRegex.Matches(data);

        StringBuilder sb = new StringBuilder();

        foreach (Match emailMatch in emailMatches)
        {
            sb.AppendLine(emailMatch.Value);
        }
        //store to file
        File.WriteAllText(outFilePath, sb.ToString());
    }
}