Can't receive email from Google Apps accounts - error 550

Can't receive email from Google Apps accounts - error 550

I am getting Error 550 when people try to send emails from gmail or Google Apps accounts

  • 550 Please turn on SMTP Authentication in your mail client. mail-yw0-f179.google.com [209.85.161.179]:34111 is not permitted to relay through this server without authentication

Everything is setup correctly - even though the Dashboard keeps saying "SPF entries in your domains DNS are not configured to match" which is wrong - I checked, but that error is showing up in everybody's Zoho Mail accounts it seems...


What should I do?