Unlike proxy/implicit relay pickup, which you may have configured on
“Configuring proxies (transparent mode only)” (if the FortiMail unit is operating in transparent mode), access control rules take effect after the FortiMail unit has initiated or received an IP and TCP-level connection at the application layer of the network.
Access control rules are categorized separately based on whether they affect either the receipt or delivery of email messages by the FortiMail unit; that is, whether the FortiMail unit initiated the SMTP session or was the destination.