It has been discovered that the company mail server is configured as an open relay. Which
of the following actions would help prevent the mail server from being used as an open
relay? (Choose TWO correct answers.)

A.
Configure netfilter to not permit port 25 traffic on the public network.

B.
Restrict Postfix to only relay outbound SMTP from the internal network.

C.
Configure Dovecot to support IMAP connectivity.

D.
Restrict Postfix to only accept e-mail for domains hosted on this server.

E.
Upgrade the mailbox format from mbox to maildir.