I cannot send Gmail by google-apps-script code

Question

function onEdit(e) {

  var ss = SpreadsheetApp.getActiveSpreadsheet();

  var sheet = ss.getActiveSheet();

  if( sheet.getSheetName() != 'Sheet1' ) { 

    return 0;

  }
var selectedCell = ss.getActiveCell();

  if( selectedCell.getColumn() == 1) { 

    var dateTimeCell = selectedCell.offset(0, 2);

    dateTimeCell.setValue('auto');

    GmailApp.sendEmail('12345@gmail.com', selectedCell.getRow(), 'hello')

}

if I modify column A and run script, Gmail sent. but if I modify column A only (don't run code), then Gmail not sent. 'auto' is inserted in both case. I suspect only GmailApp.sendEmail is not working.

why?

Answer 1

Do you have a trigger set up for it? The function you have only shows a simple trigger onEdit() which cannot send emails. See Restrictions here.

Answer 2

Vytautas is right. It says that:

They cannot access services that require authorization. For example, a simple trigger cannot send an email because the Gmail service requires authorization, but a simple trigger can translate a phrase with the Language service, which is anonymous.