PLANET SG-1000 - Manual (Page 142)

STEP 4 Group the services (DNS, FTP, HTTP, POP3, SMTP…) that provided and
used by server in Service function. And add a new service group for server
to send mails at the same time.
Service Setting
STEP 5 Add a policy that includes settings of STEP3, 4 in Incoming Policy.
Complete the Incoming Policy
STEP 6 Add a policy that includes STEP2, 4 in Outgoing Policy. It makes the server
to send e-mail to external mail server by mail service.
Complete the Outgoing Policy