554 5.7.1: Relay access denied

hi
I have configured a mail server on a SLS xserve but I have some problems with incoming emails: using any email account to send a test mail to user@mydomain.com (which is a valid account I can use to send messages), I receive the following error:


----- The following addresses had permanent fatal errors -----
<user@mydomain.com>
(reason: 554 5.7.1 <user@mydomain.com>: Relay access denied)

----- Transcript of session follows -----
... while talking to mail.mydomain.com.:
DATA
<<< 554 5.7.1 <user@mydomain.com>: Relay access denied
554 5.0.0 Service unavailable
<<< 554 5.5.1 Error: no valid recipients



I have read some topics on this forum with similar issues but I couldn't solve mine, I'll post my postconf -n


biff = no
command_directory = /usr/sbin
config_directory = /etc/postfix
content_filter = smtp-amavis:[127.0.0.1]:10024
daemon_directory = /usr/libexec/postfix
debug peerlevel = 2
enable serveroptions = yes
header_checks = pcre:/etc/postfix/custom headerchecks
html_directory = /usr/share/doc/postfix/html
inet_interfaces = all
mail_owner = _postfix
mailbox sizelimit = 0
mailbox_transport = dovecot
mailq_path = /usr/bin/mailq
manpage_directory = /usr/share/man
message sizelimit = 10485760
mydomain = mydomain.com
mydomain_fallback = localhost
mynetworks = 127.0.0.0/8
newaliases_path = /usr/bin/newaliases
queue_directory = /private/var/spool/postfix
readme_directory = /usr/share/doc/postfix
recipient_delimiter = +
relayhost =
sample_directory = /usr/share/doc/postfix/examples
sendmail_path = /usr/sbin/sendmail
setgid_group = _postdrop
smtpd clientrestrictions = permit_mynetworks permit saslauthenticated permit
smtpd enforcetls = no
smtpd helorequired = yes
smtpd helorestrictions = reject invalid_helohostname reject non_fqdn_helohostname
smtpd pw_server_securityoptions = cram-md5
smtpd recipientrestrictions = permit saslauthenticated permit_mynetworks reject unauthdestination check policyservice unix:private/policy permit
smtpd sasl_authenable = yes
smtpd tlsCAfile = /etc/certificates/mydomain.347A9DC2B6519982A6C3D71607EB9E0A466636CB.chain.pem
smtpd tls_certfile = /etc/certificates/mydomain.347A9DC2B6519982A6C3D71607EB9E0A466636CB.cert.pem
smtpd tls_excludeciphers = SSLv2, aNULL, ADH, eNULL
smtpd tls_keyfile = /etc/certificates/mydomain.347A9DC2B6519982A6C3D71607EB9E0A466636CB.key.pem
smtpd tlsloglevel = 0
smtpd use_pwserver = yes
smtpd usetls = yes
unknown local_recipient_rejectcode = 550
virtual aliasmaps =


is there any error?
any help is greatly greatly appreciated
thanks in advance

Message was edited by: novantadue

Message was edited by: novantadue