Hi guys,
in our organization we are using Exchange 2013 latest build, we pick up the emails using our POP 3 connector from the domain registra and send usining our ISP Smarthost using port 25 because port 587 never works.
lately every emails we sent its bounce back with the warning '550-Message refused by spam filter |
Can you please advise how to fix this irritating issue ?
a much appreciate it