An AppScript to automatically delete your gmail emails on a rolling window.

auto-delete-emails.gs

const RETENTION_DAYS = 30

function deleteOldEmails() {
  const maxDate = new Date();
  maxDate.setDate(maxDate.getDate() - RETENTION_DAYS);

  const formattedDate = Utilities.formatDate(maxDate, Session.getScriptTimeZone(), 'yyyy/MM/dd');
  const query = 'before:' + formattedDate;
  
  Logger.log('--- Gmail Cleanup Started ---');
  Logger.log('Query: ' + query);
  Logger.log('Running at: ' + new Date());

  // Search for old threads
  const threads = GmailApp.search(query);
  Logger.log('Found ' + threads.length + ' threads to delete (older than ' + RETENTION_DAYS + ' days).');

  let deletedCount = 0;
  const batchSize = 100;

  for (let i = 0; i < threads.length; i += batchSize) {
    const batch = threads.slice(i, i + batchSize);
    GmailApp.moveThreadsToTrash(batch);
    deletedCount += batch.length;
    Logger.log('Deleted batch ' + (i / batchSize + 1) + ': ' + batch.length + ' threads.');
  }

  Logger.log('Total deleted: ' + deletedCount + ' threads.');
  Logger.log('Cleanup finished at: ' + new Date());
  Logger.log('-----------------------------');
}

I migrated away from gmail a long time ago, and have emails forwarded to new provider. I don't particularly want any data kept within my gmail account, and the end goal is to disconnect from gmail entirely.

I have set this script up as a project in Apps Script, and the trigger will run this function every day at around midnight.

Set RETENTION_DAYS to your preferred retention period.