Is there way start a loop in a certain date range

I believe your goal is as follows.

• You want to reduce the process cost of the search of value from a large sheet.
• You want to achieve this using Google Apps Script.
• In your situation, by searching the values from the columns "A" and "F", you want to send emails.

In order to search the values from a sheet, there are several methods. Using for loop, TextFinder and query language. In my test, when the query language is used, the process cost was the lowest of these 3 patterns. So, in this answer, I would like to propose to search the values using use the query language. Ref

Sample script:

function Google_Check_Lead_Values() {
  var title = "Google | Leads"
  var Def_url = "###"; // Please use your Spreadsheet URL.
  var ss = SpreadsheetApp.openByUrl(Def_url);

  const spreadsheetId = ss.getId();
  const today = new Date();
  const tommorow = new Date();
  tommorow.setDate(tommorow.getDate() + 1);
  const vToday = Utilities.formatDate(today, Session.getScriptTimeZone(), "yyyy-MM-dd");
  const vTommorow = Utilities.formatDate(tommorow, Session.getScriptTimeZone(), "yyyy-MM-dd");
  const sheetName = "Google | Leads";
  const query = `SELECT * WHERE A >= DATE '${vToday}' AND A < date '${vTommorow}' AND E = 'az-'`;
  const url = `https://docs.google.com/spreadsheets/d/${spreadsheetId}/gviz/tq?sheet=${sheetName}&tqx=out:csv&tq=${query}`;
  const res = UrlFetchApp.fetch(encodeURI(url), { headers: { authorization: "Bearer " + ScriptApp.getOAuthToken() } });
  const [, ...values] = Utilities.parseCsv(res.getContentText());
  if (values.length == 0) return;
  values.forEach(_ => {
    MailApp.sendEmail({
      to: "email1",
      //cc: "email2",
      subject: "Discrepancy found on " + title,
      htmlBody: "Hi Team, <br>This is an automated notifcation to let you know that an issue was found on " + title + ". Please take a look at the sheet linked below: <br><br> email"
    });
  });
}

• When this script is run, the today date values are searched from the column "A", and also it searches whether the cell value of column "F" is the value of az-. When the values are found, the emaiil is sent. In this case, from your showing script, for example, when 2 rows are found, 2 emails are sent.

• If you know the Spreadsheet ID, you can also directly use it to const spreadsheetId = ss.getId(); like const spreadsheetId = "###SpreadsheetID###";.

• In this sample script, about the search of the column "F", it seaches whether the value is az-. But, if you want to search the length of cell value, please modify as follows.

  • From

      const query = `SELECT * WHERE A >= DATE '${vToday}' AND A < date '${vTommorow}' AND E = 'az-'`;
    

  • To

      const query = `SELECT * WHERE A >= DATE '${vToday}' AND A < date '${vTommorow}' AND E MATCHES '^.{0,3}$'`;
    

References:

• Query Language Reference (Version 0.7)
• Related thread.
  • https://stackoverflow.com/a/56663884