Is it possible that the email validation regx is missing some specific formats?
I added this to allow for all types. It is a bit long one of my many Google searches:
StringBuilder objString = new StringBuilder();
???objString.Append("(?:(?:\\r\\n)?[ \\t])*(?:(?:(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t]");
???objString.Append(")+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:");
???objString.Append("\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(");
???objString.Append("?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ ");
???objString.Append("\\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\0");
???objString.Append("31]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\");
???objString.Append("](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+");
???objString.Append("(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:");
???objString.Append("(?:\\r\\n)?[ \\t])*))*|(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z");
???objString.Append("|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)");
???objString.Append("?[ \\t])*)*\\<(?:(?:\\r\\n)?[ \\t])*(?:@(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\");
???objString.Append("r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[");
???objString.Append(" \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)");
???objString.Append("?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t]");
???objString.Append(")*))*(?:,@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[");
???objString.Append(" \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*");
???objString.Append(")(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t]");
???objString.Append(")+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*)");
???objString.Append("*:(?:(?:\\r\\n)?[ \\t])*)?(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+");
???objString.Append("|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r");
???objString.Append("\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:");
???objString.Append("\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t");
???objString.Append("]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031");
???objString.Append("]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](");
???objString.Append("?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?");
???objString.Append(":(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?");
???objString.Append(":\\r\\n)?[ \\t])*))*\\>(?:(?:\\r\\n)?[ \\t])*)|(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?");
???objString.Append(":(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?");
???objString.Append("[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*)*:(?:(?:\\r\\n)?[ \\t])*(?:(?:(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] ");
???objString.Append("\\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|");
???objString.Append("\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>");
???objString.Append("@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|");
???objString.Append(Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t]");
???objString.Append(")*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\");
???objString.Append("" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?");
???objString.Append(":[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[");
???objString.Append("\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*|(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-");
???objString.Append("\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(");
???objString.Append("?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*)*\\<(?:(?:\\r\\n)?[ \\t])*(?:@(?:[^()<>@,;");
???objString.Append(":\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([");
???objString.Append("^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\");
???objString.Append(Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\");
???objString.Append("]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*(?:,@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\");
???objString.Append("[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\");
???objString.Append("r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] ");
???objString.Append("\\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]");
???objString.Append("|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*)*:(?:(?:\\r\\n)?[ \\t])*)?(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\0");
???objString.Append("00-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\");
???objString.Append(".|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,");
???objString.Append(";:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?");
???objString.Append(":[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*))*@(?:(?:\\r\\n)?[ \\t])*");
???objString.Append("(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".");
???objString.Append("\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t])*(?:[");
???objString.Append("^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]");
???objString.Append("]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*\\>(?:(?:\\r\\n)?[ \\t])*)(?:,\\s*(");
???objString.Append("?:(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\");
???objString.Append("" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(");
???objString.Append("?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[");
???objString.Append("\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t");
???objString.Append("])*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t");
???objString.Append("])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?");
???objString.Append(":\\.(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|");
???objString.Append("\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*|(?:");
???objString.Append("[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\");
???objString.Append("]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*)*\\<(?:(?:\\r\\n)");
???objString.Append("?[ \\t])*(?:@(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[");
???objString.Append(Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)");
???objString.Append("?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>");
???objString.Append("@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*(?:,@(?:(?:\\r\\n)?[");
???objString.Append(" \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,");
???objString.Append(";:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:\\r\\n)?[ \\t]");
???objString.Append(")*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\");
???objString.Append("" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*)*:(?:(?:\\r\\n)?[ \\t])*)?");
???objString.Append("(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".");
???objString.Append("\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])*)(?:\\.(?:(?:");
???objString.Append("\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z|(?=[\\[");
???objString.Append("" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|" + Convert.ToChar(34) + "(?:[^\\" + Convert.ToChar(34) + "\\r\\\\]|\\\\.|(?:(?:\\r\\n)?[ \\t]))*" + Convert.ToChar(34) + "(?:(?:\\r\\n)?[ \\t])");
???objString.Append("*))*@(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])");
???objString.Append("+|\\Z|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*)(?:\\");
???objString.Append(".(?:(?:\\r\\n)?[ \\t])*(?:[^()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\] \\000-\\031]+(?:(?:(?:\\r\\n)?[ \\t])+|\\Z");
???objString.Append("|(?=[\\[" + Convert.ToChar(34) + "()<>@,;:\\\\" + Convert.ToChar(34) + ".\\[\\]]))|\\[([^\\[\\]\\r\\\\]|\\\\.)*\\](?:(?:\\r\\n)?[ \\t])*))*\\>(?:(");
???objString.Append("?:\\r\\n)?[ \\t])*))*)?;\\s*)");
???Regex regx = new Regex(objString.ToString());
???return regx.IsMatch(strEmail);