Parse & save Email Id's from File With Regex

public class EmailSeprator
{
private string[] Parse(string idString)
{
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]*)?)$";
return Regex.Split(idString.Trim(), pattern, RegexOptions.IgnoreCase);
}

public int Save(string Ids)
{
ArrayList mails=new ArrayList();
string[] listMails=Parse(Ids);
mails.AddRange(listMails);
SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings.Get("ConnectionString"));
SqlDataAdapter sda = new SqlDataAdapter("Select Email from Testing", con);
DataSet DsSql = new DataSet();
sda.Fill(DsSql, "Emails");
for (int i = 0; i < listMails.Length; i++)
{

DataRow dr = DsSql.Tables["Emails"].NewRow();
dr["Email"] = mails[i].ToString();
DsSql.Tables["Emails"].Rows.Add(dr);
}

return sda.Update(DsSql);
}
}