[rfcr]

Могу только выложить конфиг своего постфикса, т.к. конфига не моего сервака никто не даст, может только наводящие вопросы удасться задать:

alias_maps = hash:/etc/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/lib/postfix
debug_peer_level = 2
html_directory = /usr/share/doc/packages/postfix/html
inet_interfaces = all
mail_owner = postfix
mailq_path = /usr/bin/mailq
manpage_directory = /usr/share/man
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
mydomain = mdomen
myhostname = itm
myorigin = $mydomain
newaliases_path = /usr/bin/newaliases
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/packages/postfix/README_FILES
relay_domains = gw.mdomen.ru
relayhost = 10.1.1.120
sample_directory = /usr/share/doc/packages/postfix/samples
sendmail_path = /usr/sbin/sendmail
setgid_group = maildrop
smtpd_banner = $myhostname ESMTP $mail_name ($mail_version)
unknown_local_recipient_reject_code = 550