# 40_exim4-config_check_data

acl_check_data:
   # Add Message-ID if missing
   warn condition = ${if !def:h_Message-ID: {1}}
        hosts = +relay_from_hosts
        message = Message-ID: <E$message_id@$primary_hostname>
		      
   # Deny unless the address list headers are syntactically correct.
   #
   # This is disabled by default because it might reject legitimate mail.
   # If you want your system to insist on syntactically valid address
   # headers, you might want to enable the following lines.
   # deny message = Message headers fail syntax check
   #	!acl = acl_whitelist_local_deny
   #    !verify = header_syntax

   # require that there is a verifiable sender address in at least
   # one of the "Sender:", "Reply-To:", or "From:" header lines.
   # deny message = No verifiable sender address in message headers
   #	!acl = acl_whitelist_local_deny
   #    !verify = header_sender

   # accept otherwise
   accept
