function onEdit(e) {
  var editedSheet = e.source.getActiveSheet();
  var editedCell = e.range;
  var row = editedCell.getRow();
  var col = editedCell.getColumn();
  
  var ySheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Y_output");

  //Check if edit is done in Sheet "X_input"
  if(editedSheet.getName()=="X_input"){
    //copy modified cell to Y_output sheet
    ySheet.getRange(row,col).setValue(e.value);


    //check if modified cell is within B2:Y61 range and send an email
    if(row>=2 && row<=61 && col>=2 && col<=25){
      //Send email
     var subject = "Sheet: "+editedSheet.getName();
      var message = "Cell "+editedCell.getA1Notation()+" was modified from '"+e.oldvalue+"' to '"+e.value+"'";
      MailApp.sendEmail("ronoel@google.com",subject,message);
    }
  }
 
}