Recipient address rejected

Galera estou com dificuldade para configurar o postfix com saslauthd, quando alguem me envia e-mail recebe mensagem Recipient address rejected, só funciona quando eu incluo a classe da minha rede no mynetworks, mais ai qualquer pesso pode usar meu servidor para disparar e-mail, se alguem puder me ajudar.

queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
mail_owner = postfix
myhostname = mail.meudominio.com.br
mydomain = meudominio.com.br
myorigin = $myhostname
inet_interfaces = all
unknown_local_recipient_reject_code = 550
mynetworks_style = subnet
mynetworks = 127.0.0.0/8
relay_domains = mail.meudominio.com.br
alias_database = hash:/etc/aliases
mail_spool_directory = /var/spool/mail
mailbox_command = /usr/bin/procmail
smtpd_banner = $myhostname ESMTP
debug_peer_level = 2
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
xxgdb $daemon_directory/$process_name $process_id & sleep 5
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.2.8/samples
readme_directory = /usr/share/doc/postfix-2.2.8/README_FILES
maps_rbl_domains = relays.ordb.org, dev.null.dk, opm.blitzed.org, sbl.spamhaus.org
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject