My mail server flagged spam!

[Chuck Swiger]

On Oct 23, 2010, at 3:46 PM, Marwan Sultan wrote:
>  they configure their outlook express to use SMTP user/password
>  with mail.clinet_domain.com as incoming/outgoing.
> 
>  even if they send from xyz at client_domain to admin at MyDomain.com
>  both are in same server, I will still receive it as SPAM.
>  (They are sending from outlook.)

When someone is an authorized user of email, ie, they login to your SMTP server via a good username+password, then you should configure your spam filtering to treat them as trusted.  For example, in postfix you could have:

smtpd_recipient_restrictions = permit_mynetworks,
        permit_sasl_authenticated,
[ ...before checks like... ]
        check_policy_service inet:127.0.0.1:12525,
        check_policy_service inet:127.0.0.1:10023,

Regards,
-- 
-Chuck