Hi, finally i can send and receive mails but when i send a mail to a friend of mine i received this error:

----- Transcript of session follows -----
... while talking to mail.sourceforge.net.:
>>> HELO zeus
<<< 550 Don't like your HELO/EHLO. Hostname must contain a dot.
... while talking to externalmx-1.sourceforge.net.:
>>> HELO zeus
<<< 550 Don't like your HELO/EHLO. Hostname must contain a dot.
554 5.0.0 Service unavailable

How can i fix this, cos i can´t reach that person.

Thanks.
Emilio

Does your mailserver have a hostname with full domain?

yes, if yout type hostname it shows conastec.com.ar

anyway i post you postconf -n results:

alias_database = hash:/etc/postfix/aliases
alias_maps = hash:/etc/postfix/aliases
canonical_maps = hash:/etc/postfix/canonical
command_directory = /usr/sbin
config_directory = /etc/postfix
content_filter = smtp-amavis:[127.0.0.1]:10024
daemon_directory = /usr/lib/postfix
debug_peer_level = 2
delay_warning_time = 4
inet_interfaces = all
mail_owner = postfix
mail_spool_directory = /var/spool/mail
mailbox_command = /usr/bin/procmail -Y -a $DOMAIN
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
myhostname = conastec.com.ar
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.0.13/README_FILES
sample_directory = /usr/share/doc/postfix-2.0.13/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtpd_banner = $myhostname ESMTP $mail_name ($mail_version) (Mandrake Linux)
unknown_local_recipient_reject_code = 450

Thanks.
Emilio.