List<string> lSubject;
string strSubject;
string strTest="";
string strCheck = "[P]";
if(pEmailHeaders.ContainsKey("subject"))
{
  lSubject = pEmailHeaders["subject"];
  strSubject = lSubject[0];
  if(strSubject.Length>3)
{
     strTest = strSubject.Substring(0,3);
   }
  if(strTest == strCheck)
  {
     lSubject[0] = strSubject.Substring(strCheck.Length,strSubject.Length-strCheck.Length);
     pEmailHeaders["subject"] = lSubject;
     return  true;
  }

}
return false;