Re: [exim] Rejecting spam if mail is relayed

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Autor: Olaf Hopp
Data:  
Para: exim-users, fanf2
Assunto: Re: [exim] Rejecting spam if mail is relayed
Tony Finch wrote:
> On Tue, 17 Jun 2008, Olaf Hopp wrote:
>> So I thought I must "somehow" modify my SA-ACL doing a "DENY" when
>> spamscore is above some treshold and final destination is not inhouse.
>>
>> I thought I could accomplish this via "address_data" set by my router,
>> which is handling remote deliveries and then asking within the data-acl
>> for the value of address_data, but it is always unset :-(
>
> Your idea is generally good. The problem is that address_data is not set
> in the data acl because its value is specific to a single address, but a
> message can have more than one recipient. What you need to do is decide
> how to deal with a message that is sent to multiple recipients some of
> which are delivered locally and some of which are forwarded. For example,
> you might decide to reject spam in this case, just like messages to one
> forwarding recipient. To implement this policy, you can set an acl_m
> variable in the rcpt acl if the address_data indicates the recipient is
> forwarded and leave it alone in other cases. Then check the acl_m variable
> in the data acl to see if it is set and reject the message if the spam
> score is too high. You can change the logic for setting the variable
> according to the ploicy you want.


Thanks Tony,
I was just about reading about the acl-variables when you answer arrived.
My solution is as follows:

rcpt_acl:
   accept  domains = +local_domains
           endpass
           message    = Unknown user.
           verify     = recipient
           set acl_m0 = $address_data


And the router handling remote deliveries:

lookuphost:
driver = dnslookup
domains = ! +local_domains
transport = remote_smtp_out
ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
address_data = remote

The router doing local deliveries does not set address_data

Further in the data_acl
   deny    message    = No relay of spam to foreign addresses
           condition  = ${if >{$spam_score_int}{50}{1}{0}}
           condition  = ${if def:acl_m0 {1}{0}}


I still have the (minor) problem as Tony pointed out to decide
what to to if there is at least one remote and one local delivery.
But this is a question of politics that technics :-)

Olaf


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    _-\<,_     Dipl.-Geophys. Olaf Hopp
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