voilà ce que j'ai dans ma config:
[root@srvlinux root]# postconf -n
alias_database = hashetc/postfix/aliases
alias_maps = hashetc/postfix/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
debug_peer_level = 2
default_destination_concurrency_limit = 10
default_privs = nobody
defer_transports = smtp
home_mailbox = Mailbox
inet_interfaces = all
local_destination_concurrency_limit = 2
mail_name = srvlinux
mail_owner = postfix
mail_spool_directory = /var/mail
mailbox_command = /usr/bin/procmail
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
mydestination = $myhostname, localhost.$mydomain $mydomain
mydomain = allser.com
myhostname = srvlinux
mynetworks = l'adresse ip du réseau/8,127.0.0.0/8 - destinations that match $inet_interfaces,
mynetworks_style = subnet
myorigin = allser.com
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-1.1.11/README_FILES
relay_domains = $mydestination
relayhost = srvlinux.allser.com
sample_directory = /usr/share/doc/postfix-1.1.11/samples
setgid_group = postdrop