554 5.7.1 <@mail>: Relay access denied

Hello,
I have configured my mail server postfix well on my Ubuntu server however at the time of l' sending email I always receive an email error:

Non remis :
Administrateur système

Certains des destinataires ou tous les destinataires n'ont pas reçu votre message.

Objet :
Date : 10/12/2008 13:02

Impossible de contacter le(s) destinataire(s) suivant(s) :

'[email protected]' le 10/12/2008 13:02
554 5.7.1 <[email protected]>: Relay access denied

 

enable SMTP server authentication in mail client

 

how to do it?

 

http://help.yahoo.com/l/us/yahoo/mail/original/mailplus/pop/pop-32.html

 

I enabled SMTP server authentication but that still does not function

 

post a content of your main.cf in /etc/postfix/ folder

 

root@srv-proxy:~# cat /etc/postfix/main.cf
# See /usr/share/postfix/main.cf.dist for a commented, more complete version
#
#
# Debian specific: Specifying a file name will cause the first
# line of that file to be used as the name. The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
#
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
#
# appending .domain is the MUA's job.
append_dot_mydomain = no
#
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
#
#
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
#
myhostname = srv-proxy.icc.com.tn
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = impactcontact.com, srv-proxy.icc.com.tn, localhost
relayhost = smtp.tunet.tn
mynetworks = 127.0.0.0/8, 192.168.0.0/24
#mailbox_command = procmail -a "$EXTENSION"
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
home_mailbox = Maildir/

 

as far as i can see you are missing these lines:
smtpd_sasl_local_domain =
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_sasl_authenticated_header = yes
smtpd_recipient_restrictions = permit_sasl_authenticated,permit_mynetworks,reject _unauth_destination
smtpd_tls_auth_only = no
smtp_use_tls = yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom

but I used
http://howtoforge.com/perfect-server-ubuntu8.04-lts
for my install

 

I have written here a small "howto" on how to relay postfix smtp through your ISP:

http://ubuntuforums.org/showpost.php?p=6348180&postcount=2

maybe that helps.