[Postfix-es] El sistema no envia correo a otros dominios

[Jose]

Tengo instalado Postfix y el problema es que no consigo que el sisteme envie 
correo a dominios externos (p.e hotmail.com, ono.com, etc)por otro lado no 
hay problema con el correo interno y con el correo dirigido a mydominio.
El servidor es unico en la red local debe dar salida al correo de todos los 
clientes de la red (192.168.0.0/24)
Tambien tengo instalado courier-imap, amavis-new y clamav
Aqui tienen la salida de postconf -n por si me pueden ayudar.
poniente:~# postconf -n
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases
command_directory = /usr/sbin
config_directory = /etc/postfix
content_filter = smtp-amavis:[127.0.0.1]:10024
daemon_directory = /usr/lib/postfix
default_destination_concurrency_limit = 10
disable_dns_lookups = no
disable_vrfy_command = yes
home_mailbox = Maildir/
inet_interfaces = all
local_destination_concurrency_limit = 2
local_recipient_maps = $alias_maps unix:passwd.byname
mail_name = Postfix/MJ-1.08
mail_owner = postfix
mailbox_command = procmail -a "$EXTENSION"
mailbox_size_limit = 0
maximal_queue_lifetime = 5d
message_size_limit = 10485760
mydestination = $myhostname localhost.$mydomain $mydomain
mydomain = ies25abril.dsland.org
myhostname = poniente.ies25abril.dsland.org
mynetworks = 127.0.0.1 192.168.0.0/24
myorigin = /etc/mailname
owner_request_special = no
queue_directory = /var/spool/postfix
recipient_delimiter = +
relay_domains = $mydomain
relayhost =
setgid_group = postdrop
smtpd_banner = $myhostname ESMTP $mail_name ($mail_version)
smtpd_data_restrictions = reject_unauth_pipelining
smtpd_recipient_restrictions = permit_mynetworks reject_unauth_destination
transport_maps = hash:/etc/postfix/transport

-- 
Jose Maria Raga
Benetússer (Valencia)
jmragap en ono.com