LinuxQuestions.org - Postfix SMTP Authentication

I'm hoping someone can help me with Postfix/Dovecot SMTP authentication.

When trying to send a test message with a mail client over the internet I get the following error:

Code:

The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was username@gmail.com'. Subject 'test', Account: 'mailgw.mydomain.com', Server: 'mailgw.mydomain.com', Protocol: SMTP, Server Response: '554 5.7.1 <username@gmail.com>: Relay access denied', Port: 25, Secure(SSL): No, Server Error: 554, Error Number: 0x800CCC79

The g-mail account is the address I'm sending to. The account i'm sending from has an account on the server and I can successfully download messages using this client. I can also log in to squirrelmail using this account. So I know that dovecot is authenticating it.

Ideally I would like anyone that can authenticate from domain example.com to be able to send mail through my server.

Below are what I think are the relevant portions of my main.cf and dovecot.conf file.

Main.cf
----------

Code:

virtual_mailbox_domains = /etc/postfix/virtual_config/virtual_domains

virtual_mailbox_maps = hash:/etc/postfix/virtual_config/virtual_mailboxes

virtual_mailbox_base = /var/spool/virtual_mail

virtual_minimum_uid = 100

virtual_uid_maps = static:501

virtual_gid_maps = static:501

virtual_alias_maps = hash:/etc/postfix/virtual_config/virtual_aliases



smtpd_sasl_auth_enable = yes

smtpd_sasl_type = dovecot

smtpd_sasl_path = private/auth

broken_sasl_auth_clients = yes

#smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_unauth_destination

smtpd_sender_restrictions = permit_sasl_authenticated, permit_mynetworks

Dovecot.conf
----------------

Code:

auth default {

  # Space separated list of wanted authentication mechanisms:

  #  plain login digest-md5 cram-md5 ntlm rpa apop anonymous gssapi otp skey

  #  gss-spnego

  # NOTE: See also disable_plaintext_auth setting.

  mechanisms = plain login cram-md5



 passdb passwd-file {

    # File contains a list of usernames, one per line

    args = /etc/postfix/virtual_config/virtual_passwords

    #args = /etc/dovecot.deny

    #deny = yes

  }



  userdb passwd {

  }

  userdb static {

        args = uid=501 gid=501 home=/var/spool/virtual_mail/%d/%n

        }



socket listen {

    #master {

      # Master socket provides access to userdb information. It's typically

      # used to give Dovecot's local delivery agent access to userdb so it

      # can find mailbox locations.

      #path = /var/run/dovecot/auth-master

      #mode = 0600

      # Default user/group is the one who started dovecot-auth (root)

      #user =

      #group =

    #}

    client {

      # The client socket is generally safe to export to everyone. Typical use

      # is to export it to your SMTP server so it can do SMTP AUTH lookups

      # using it.

      #path = /var/run/dovecot/auth-client

      path = /var/spool/postfix/private/auth

      mode = 0660

      user = postfix

      group = postfix

    }

 }

}

Any help is much appreciated. This server hosts e-mail for multiple domains and it's done with virtual users.