vestacp-docker/vesta/etc/exim4/conf.d/acl/40_exim4-config_check_data

### acl/40_exim4-config_check_data
#################################

# This ACL is used after the contents of a message have been received. This
# is the ACL in which you can test a message's headers or body, and in
# particular, this is where you can invoke external virus or spam scanners.

acl_check_data:

  # Deny unless the address list headers are syntactically correct.
  #
  # If you enable this, you might reject legitimate mail.
  .ifdef CHECK_DATA_VERIFY_HEADER_SYNTAX
  deny
    message = Message headers fail syntax check
    !acl = acl_local_deny_exceptions
    !verify = header_syntax
  .endif


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


  # Deny if the message contains malware. Before enabling this check, you
  # must install a virus scanner and set the av_scanner option in the
  # main configuration.
  #
  # exim4-daemon-heavy must be used for this section to work.
  #
  # deny
  #   malware = *
  #   message = This message was detected as possible malware ($malware_name).


  # Add headers to a message if it is judged to be spam. Before enabling this,
  # you must install SpamAssassin. You also need to set the spamd_address
  # option in the main configuration.
  #
  # exim4-daemon-heavy must be used for this section to work.
  #
  # Please note that this is only suiteable as an example. There are
  # multiple issues with this configuration method. For example, if you go
  # this way, you'll give your spamassassin daemon write access to the
  # entire exim spool which might be a security issue in case of a
  # spamassassin exploit.
  #
  # See the exim docs and the exim wiki for more suitable examples.
  #
  # warn
  #   spam = Debian-exim:true
  #   add_header = X-Spam_score: $spam_score\n\
  #             X-Spam_score_int: $spam_score_int\n\
  #             X-Spam_bar: $spam_bar\n\
  #             X-Spam_report: $spam_report


  # This hook allows you to hook in your own ACLs without having to
  # modify this file. If you do it like we suggest, you'll end up with
  # a small performance penalty since there is an additional file being
  # accessed. This doesn't happen if you leave the macro unset.
  .ifdef CHECK_DATA_LOCAL_ACL_FILE
  .include CHECK_DATA_LOCAL_ACL_FILE
  .endif


  # accept otherwise
  accept