On 27 January 2017 at 23:47, Roberto Fulgado <[email protected]> wrote:
> Hi All,
>
> First of all I wanted to let you know that I just recently started using
> postfix as our
> mail server. We've been using sendmail for a long time. I have a question on
> RBL
> whitelisting. I have done internet search on how to do it but I can't seem
> to whitelist
> some senders.
>
>
> From what I understand, I can only white list mail server's FQDN
> or it's IP address.
>
> Is there a way to white list by sender's domain name and sender's
> email address.
>

I suggest you visit http://www.postfix.org/postconf.5.html and search
for 'check_' this will show you the many types of whitelist that are
possible with the various restriction lists.

Regarding restriction lists, as I understand it emails are checked
against them in this order (if they exist):
1 smtpd_client_restrictions
2 smtpd_helo_restrictions
3 smtpd_sender_restrictions      (normally 1-3 are all evaluated after
RCPT TO or ETRN)
4 smtpd_relay_restrictions        (after RCPT TO)
5 smtpd_recipient_restrictions    (after RCPT TO)
6 smtpd_data_restrictions        (can reject at DATA)
7 smtpd_end_of_data_restrictions (can reject at END-OF-DATA)
8 smtpd_etrn_restrictions        (can reject at ETRN)

In each restriction list that is specified in main.cf are a series of
access tests carried out in order, and in each of these access tests
an email's further progress depends on when/if it matches to a test in
which case an 'action' is carried out
(http://www.postfix.org/access.5.html), the common ones being:
   REJECT: decisively reject the email
   OK: any remaining checks in this access test and in this
restriction list are skipped - but not subsequent lists, to which the
email will be submitted
   DUNNO : any remaining checks in this access test are skipped - but
not subsequent tests in this restriction list nor any subsequent
lists, to which the email will be submitted

Afterwards come non-restriction-list-based processing including:
  header_checks                 (can only be processed after the mail
has been received, so is slower)
  body_checks                 (ditto, and even slower)
  content_filter e.g. amavis    (very slow)

I can't think of an easy way to whitelist by the internal 'From:'
address because this can't be checked until header_checks which
however runs after all restriction lists (is this right?).

If I've said something wrong here hopefully someone will correct me
(and I will learn!)

Dominic

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