Clarkconnect in Relay ANTISPAM

[supernoob]

I configured a Clarkconnect (with Postfix + SpamAssassin) to our server for Mail Exchange (SBS2003). I use the option relay_recipients_maps with a perl script (cron) that will search the LDAP alias all existing mail on the Exchange server. I therefore references with ipcop port 25 of our external IP to Clarkconnect now everything works pretty well, here are some options that I added:

smtpd_helo_required = yes
smtpd_sender_restrictions = reject_unknown_sender_domain, reject_non_fqdn_hostname, reject_non_fqdn_sender, reject_invalid_hostname
relay_recipient_maps = hash:/etc/postfix/relay_recipients
show_user_unknown_table_name = No
header_checks = regexp:/etc/postfix/header_checks
mime_header_checks = regexp:/etc/postfix/mime_header_checks

However new messages from exchange are emerging, it would seem that either the mails sent by spammers with internal addresses Sender that do not, once we receive the information for non-delivery:

From: System Administrator
Subject: Undeliverable: [SPAM] Activity on your current account

Your message

To: Webmaster
Subject: [SPAM] Activity on your current account
Sent: Mon, 8 Jun 2009 15:59:11 +0200

did not reach the following recipient(s):

Webmaster on Mon, 8 Jun 2009 16:00:12 +0200

The mail system was unable to deliver this message but did not
reported a specific reason. Check the address of the recipient and
try to send the message. If it still fails, contact
your system administrator.

My question is: why do we have, with Postfix + SpamAssassin, such messages whereas before it was not?

[Snake08]

Out of curiosity what became the smtpd_client_restrictions parameter in your configuration? It is something that I do not understand. I do not use "relay_recipient_maps, and recipient verification using a static file:
smtpd_recipient_restrictions = ...
check_recipient_access hash: / etc / postfix / access_recipient

[supernoob]

Here the parameter smtpd_recipient_restrictions:

smtpd_recipient_restrictions = permit_mynetworks, permit_mynetworks, reject_unauth_destination

I must add a map in addition to the smtpd_recipient_restrictions relay_recipient? I thought that in this configuration the relay_recipient is enough.

[Snake08]

Ok no problem with smtpd_recipient_restrictions. Otherwise something hurts me in your configuration but I do not have time to watch today.

[supernoob]

thank you for the answer! Something hurts you: the fact that Exchange returns "undeliverable" because of spammers who use our addresses to spam? In any case, the duo Postfix + SpamAssassin is very efficient except for this problem.