Go to Configuration → Traffic Policy to add rules for services that will be available from the Internet. Rules for service mapping should be always at the top of the traffic rules table.
Mapping of local FTP server — unsecured access only is supposed which makes it possible to filter traffic and scan it for viruses.
Access to other mail server services (save SMTP) — allowed from certain IP addresses only.
Notes:
This rule enables access to IMAP and POP3 services in both encrypted and unencrypted versions — client can select which service they will use.
Based on this example, the SMTP service was mapped by the traffic rules Wizard (refer to chapter 2.4 Basic Traffic Policy Configuration) — the appropriate rule already exists.
Access to the SMTP service must not be limited to certain IP addresses only as anyone is allowed to send an email to the local domain.