A client wants to receive email notifications as soon as someone edits a Google Spreadsheet that is shared with a team of people. Google Docs supports the onEdit() trigger that runs whenever an edit is made to any cell of the sheet but a limitation is that the onEdit trigger cannot send emails. Nor can be used to call external API though the URLFetch service.

As a workaround, the edits were stored as a Property and another time-based trigger would periodically send the stored value by email.

/**
 * @OnlyCurrentDoc
 */

function onEdit(e) {

    var key = "ROWCHANGES";

    var range = e.range;

    var date = Utilities.formatDate(new Date(), e.source.getSpreadsheetTimeZone(), "dd-MM-yy HH:MM:s");

    var properties = PropertiesService.getUserProperties();

    var sheet = e.source.getActiveSheet();

    var data = sheet.getRange(range.getRow(), 1, 1, sheet.getLastColumn()).getValues()[0];

    data[range.getColumn() - 1] = "<b>" + data[range.getColumn() - 1] + "</b>";

    var edits = {
        name: sheet.getSheetName(),
        data: data
    };

    var existing = JSON.parse(properties.getProperty(key)) || {};

    existing[date] = edits;

    properties.setProperty(key, JSON.stringify(existing));

}

function onEdit_Email() {

    var properties = PropertiesService.getUserProperties();

    var json = JSON.parse(properties.getProperty("ROWCHANGES"));

    var html = "":

        for (var keys in json) {

            html = html + "<br>[" + keys + "][" + json[keys].name + "] &mdash; " + json[keys].data;

        }

    if (html !== "") {

        MailApp.sendEmail(email, subject, "", {
            htmlBody: html
        });

        properties.deleteAllProperties();

    }

}