[postfix-es] Rechazar FROM nulos

[Maximiliano Alonzo]

Hola lista:
   Resulta que al pasarle un Nessus contra mi servidor de correo, este me informo que el mismo permite el envio con "FROM: <>" nulos, lo cual puede ser utilizado para spam.
   Realize una prueba a mano y efectivamente es asi, aca esta lo que hice.

malonzo en wksadmin:~> telnet 192.168.1.230 smtp
Trying 192.168.1.230...
Connected to 192.168.1.230.
Escape character is '^]'.
220 correo.eufores.com.uy ESMTP Postfix 2.0.18 (2.0.18)
EHLO ejemplo.com
250-correo.eufores.com.uy
250-PIPELINING
250-SIZE 31457280
250-ETRN
250-XVERP
250 8BITMIME
MAIL FROM: <>
250 Ok
RCPT TO: <malonzo en adinet.com.uy>
250 Ok
DATA
354 End data with <CR><LF>.<CR><LF>
prueba de correo
.
250 Ok: queued as 5192D18340A
quit
221 Bye
Connection closed by foreign host.
malonzo en wksadmin:~> 

Como puedo hacer para que esto no sea posible??

Aca esta mi postconf -n

alias_maps = mysql:/opt/postfix-2.0.18/etc/virtual.cf
command_directory = /opt/postfix-2.0.18/sbin
config_directory = /opt/postfix-2.0.18/etc
content_filter = vscan
daemon_directory = /opt/postfix-2.0.18/libexec
debug_peer_level = 2
default_destination_concurrency_limit = 10
disable_vrfy_command = yes
inet_interfaces = all
local_destination_concurrency_limit = 2
mail_name = Postfix 2.0.18
mail_owner = postfix
mailq_path = /usr/bin/mailq
manpage_directory = /opt/postfix-2.0.18/man
message_size_limit = 31457280
mydestination = $myhostname, localhost.$mydomain, $mydomain, $transport_maps
mydomain = eufores.com.uy
myhostname = correo.eufores.com.uy
mynetworks = 127.0.0.0/8, 192.168.1.0/24, 192.168.2.0/24, 192.168.3.0/24, 192.168.
5.0/24, 192.168.6.0/24, 192.168.8.0/24, 192.168.9.0/24, 192.168.10.0/24,192.168.11
.0/24, 192.168.12.0/24, 192.168.13.0/24, 192.168.15.0/24, 192.168.16.0/24, 192.168
.18.0/24
myorigin = $mydomain
newaliases_path = /usr/bin/newaliases
notify_classes = bounce, 2bounce, delay, resource, software, protocol, policy
queue_directory = /opt/postfix-2.0.18/var/spool
readme_directory = /opt/postfix-2.0.18/readme
sample_directory = /opt/postfix-2.0.18/sample
sendmail_path = /usr/sbin/sendmail
setgid_group = postdrop
smtpd_banner = $myhostname ESMTP $mail_name ($mail_version)
smtpd_helo_required = yes
smtpd_recipient_restrictions = permit_mynetworks        check_relay_domains
transport_maps = mysql:/opt/postfix-2.0.18/etc/transport.cf
virtual_alias_maps = mysql:/opt/postfix-2.0.18/etc/virtual.cf
virtual_gid_maps = mysql:/opt/postfix-2.0.18/etc/gids.cf
virtual_mailbox_base = /
virtual_mailbox_maps = mysql:/opt/postfix-2.0.18/etc/mysql_virt.cf
virtual_uid_maps = mysql:/opt/postfix-2.0.18/etc/uids.cf

Desde ya muy agradecido.
		Maximiliano Alonzo


*-------------------------------------------*
*       Administrador Sistemas Linux        *
*          malonzo en eufores.com.uy           *
*             Eufores - ENCE                *
*           www.eufores.com.uy              *
*-------------------------------------------*
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