Roland Vogt wrote:

>I'm using Cluebringer with Postfix and I have some troubles. When I
>try to send a mail from Thunderbird, I get this error : "Sender
>address rejected, try again later".



>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]: 127.0.0.1:10031:
>wanted attribute: action
>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]: input attribute 
>name: action
>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]: input attribute 
>value: DUNNO
>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]: 127.0.0.1:10031:
>wanted attribute: (list terminator)
>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]: input attribute 
>name: (end)
>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]:
>check_table_result: inet:127.0.0.1:10031 DUNNO policy query

OK, so this bit says the policy server said "DUNNO", so Postfix then 
moves on to the next check :

>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]: generic_checks:
>name=check_policy_service status=0
>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]: generic_checks: name=defer

And the next check said defer, so that's what Postfix said to the client :

>Aug 30 09:18:34 testing-puppet postfix/smtpd[7331]: NOQUEUE: reject:
>RCPT from unknown[192.168.170.85]: 450 4.3.2 <[email protected]>:
>Sender address rejected: Try again later; from=<[email protected]>
>to=<[email protected]> proto=ESMTP helo=<[192.168.170.85]>



>[main.cf]
>  ...
>smtpd_sender_restrictions = check_policy_service inet:127.0.0.1:10031 defer
>#smtpd_recipient_restrictions = check_policy_service
>inet:192.186.254.242:10031 defer
>#smtpd_end_of_data_restrictions = check_policy_service
>inet:192.168.254.242:10031 defer

Both these checks say that if a previous check doesn't explicitly say 
yes, then defer the mail. Cluebringer only says "no" (reject or 
defer), or "dunno" which means "it passes my checks, see what else 
you've got". If it said "yes" then it would make it far less flexible 
as it would mean you couldn't have any other useful checks after the 
call to Cluebringer.

I'd strongly recommend you put a bit more in your sender and client 
checks. There are a few simple things you can add that will help a 
lot with spam.


FYI, here's an extract from my main.cf. I'll leave you to look up 
what each check is doing (http://www.postfix.org/postconf.5.html) - 
one's that help enormously with spam are :
   reject_non_fqdn_hostname,
   reject_invalid_hostname,
smtpd_helo_required = yes
These require the client to send a "HELO" or "EHLO" command, and 
reject clients that don't supply a valid FQDN - but don't be tempted 
to try doing a DNS lookup (reject_unknown_helo_hostname) on it to 
verify as that creates no end of false positives.

   reject_unauth_pipelining,
Then many spammers ignore some protocol niceties and just spew data 
at use, so we reject them.

   check_helo_access hash:/etc/postfix/helo_access,
This one lets us have a black/whitelist of things that can be in the 
HELO field, and contains things like :
<our FQDN>      500 Error validating hostname, connection rejected.
<our IP address>        500 Error validating hostname, connection rejected.
As I've found a lot of spammers will just use our hostname or address 
in their HELO command.

Then notice that all of the restrictions sections end with "permit". 
Pretty well all the checks are negative only - ie they can say no, 
but don't say yes (only "dunno"). I think permit is inferred, but I'm 
one for explicit outcomes.
So, each check has a chance to say no - in which case the mail is 
rejected; otherwise it says dunno and Postfix falls through to the 
next step.

# Requirements for the HELO statement
smtpd_helo_restrictions =
   check_client_access cidr:/etc/postfix/host_access,
   permit_mynetworks,
   permit_sasl_authenticated,
   check_helo_access hash:/etc/postfix/helo_access,
   reject_non_fqdn_hostname,
   reject_invalid_hostname,
   permit

# Requirements for the sender details
smtpd_sender_restrictions =
   check_client_access cidr:/etc/postfix/host_access,
   permit_mynetworks,
   hash:/etc/postfix/access,
   permit_sasl_authenticated,
   reject_non_fqdn_sender,
   reject_unknown_sender_domain,
   permit

## Requirements for the connecting server
smtpd_client_restrictions =
   permit_mynetworks,
   check_client_access cidr:/etc/postfix/blacklist,
   permit

# Requirement for the recipient address
smtpd_recipient_restrictions =
   permit_mynetworks,
   reject_unauth_pipelining,
   check_client_access cidr:/etc/postfix/host_access,
   check_policy_service inet:<some IP>:10031,
   permit_sasl_authenticated,
   reject_non_fqdn_recipient,
   reject_unknown_recipient_domain,
   reject_unlisted_recipient,
   reject_unauth_destination,
   reject_rbl_client zen.spamhaus.org,
   permit


smtpd_end_of_data_restrictions =
   check_policy_service inet: <some IP>:10031,
   permit


## require proper helo at connections
smtpd_helo_required = yes
## waste spammers time before rejecting them
smtpd_delay_reject = yes
disable_vrfy_command = yes

-- 
Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.
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