A. The FortiMail unit tracks the /32 bit host address of the sender.
B. When an email is received from a new sender IP address, envelope sender and envelope recipient addresses, the FortiMail unit will initially send a temporary failure message.
C. After the initial temporary fail message is sent, the message must be retransmitted between the Greylisting period expiry and initial expiry time periods.
D. Pass-through is allowed until the configured TTL expires.
E. An ACL with action Relay bypasses Greylisting.