Amazon SES outbound Error

Hi,
We were succesfully using phabricator until recently when the outbounds emails stopped working, the logs are as follows:

Reading message body from stdin...
[2021-06-15 07:02:34] EXCEPTION: (SimpleEmailServiceException) Unexpected HTTP status while making request to Amazon SES: expected 200, got 403. at [<phabricator>/externals/amazon-ses/ses.php:509]
arcanist(head=master, ref.master=65cda1596f25), phabricator(head=master, ref.master=205657ac76a2)
  #0 SimpleEmailServiceRequest::getResponse called at [<phabricator>/externals/amazon-ses/ses.php:253]
  #1 SimpleEmailService::sendRawEmail called at [<phabricator>/src/applications/metamta/adapter/PhabricatorMailAmazonSESAdapter.php:64]
  #2 PhabricatorMailAmazonSESAdapter::executeSend called at [<phabricator>/externals/phpmailer/class.phpmailer-lite.php:592]
  #3 PHPMailerLite::Send called at [<phabricator>/src/applications/metamta/adapter/PhabricatorMailAmazonSESAdapter.php:45]
  #4 PhabricatorMailAmazonSESAdapter::sendMessage called at [<phabricator>/src/applications/metamta/storage/PhabricatorMetaMTAMail.php:750]
  #5 PhabricatorMetaMTAMail::sendWithMailers called at [<phabricator>/src/applications/metamta/storage/PhabricatorMetaMTAMail.php:555]
  #6 PhabricatorMetaMTAMail::sendNow called at [<phabricator>/src/applications/metamta/PhabricatorMetaMTAWorker.php:22]
  #7 PhabricatorMetaMTAWorker::doWork called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorWorker.php:124]
  #8 PhabricatorWorker::executeTask called at [<phabricator>/src/infrastructure/daemon/workers/PhabricatorWorker.php:163]
  #9 PhabricatorWorker::scheduleTask called at [<phabricator>/src/applications/metamta/storage/PhabricatorMetaMTAMail.php:525]
  #10 PhabricatorMetaMTAMail::save called at [<phabricator>/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php:228]
  #11 PhabricatorMailManagementSendTestWorkflow::execute called at [<arcanist>/src/parser/argument/PhutilArgumentParser.php:492]
  #12 PhutilArgumentParser::parseWorkflowsFull called at [<arcanist>/src/parser/argument/PhutilArgumentParser.php:377]
  #13 PhutilArgumentParser::parseWorkflows called at [<phabricator>/scripts/mail/manage_mail.php:21]

I have even tried creating a new SES User and created the credentials for the same but with no luck. If anyone has faced a similar issue please let me know how to get over this.

The error that phabricator is indicating is that it received a 403 from Amazon’s SES service instead of a successful 200. This looks like an issue with the SES account or credentials which might have changed, and not an issue with phabricator.