Re: [exim] anti-spam pointers please

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Author: Odhiambo Washington
Date:  
To: exim users
Subject: Re: [exim] anti-spam pointers please
On Wed, 3 Apr 2019 at 11:55, Odhiambo Washington <odhiambo@???> wrote:

>
>
> On Wed, 3 Apr 2019 at 11:27, Rory Campbell-Lange <rory@???>
> wrote:
>
>> On 02/04/19, Odhiambo Washington via Exim-users (exim-users@???)
>> wrote:
>> > On Mon, 1 Apr 2019 at 22:12, Rory Campbell-Lange via Exim-users <
>> > exim-users@???> wrote:
>> >
>> > > It's some years since I've spent time tweaking my exim setup to
>> receive
>> > > spam. I've forgotten any skills I might once have had in this area.
>>
>> > Hello Rory,
>> >
>> > Long time!
>> >
>> > Lately, you can also substitute rspamd for SpamAssassin.
>> > I hope you are also doing rDNS checks. They help me block many spammers
>> too.
>>
>> Hi Odhiambo. Lovely to receive an email from you after all these years!
>>
>> I've spent some time looking at the rspamd website following your
>> mention of it. I'll turn to that if I can't improve my spamassassin
>> performance!
>>
>> For RDNS do you recommend something along the lines of
>>
>>         drop    message     = REJECTED - Sender Verify Failed and no RDNS
>>                         log_message = REJECTED - Sender Verify Failed and
>> no RDNS
>>                         !verify = reverse_host_lookup
>>                         !verify = sender/callout=2m,defer_ok
>>                         !condition =  ${if eq{$sender_verify_failure}{}}

>>
>> (reference https://github.com/Exim/exim/wiki/Verification)
>>
>> Kind regards
>> Rory
>>
>
> Hi Rory,
>
> Yes, you can do that, but I would actually split the test into two for
> clarity in logging.
>
>
> deny message       = REJECTED - rDNS Verify Failed
>         log_message = rDNS fail for $sender_host_address
> # check only port 25, not users submitting on port 587
>         condition       = ${if eq{$interface_port}{25}}
>         !verify            = reverse_host_lookup

>
>
> I would do the sender verification check separately:
>
> deny    message      = REJECTED - Sender Verify Failed
>           log_message = REJECTED - Sender Verify Failed for $sender_address
>           !verify            = sender/callout=2m,defer_ok,
>           !condition      =  ${if eq{$sender_verify_failure}{}}

>
> YMMV.
>
>

I hasten to add that I prefer to do sender verification in acl_smtp_rcpt.

--
Best regards,
Odhiambo WASHINGTON,
Nairobi,KE
+254 7 3200 0004/+254 7 2274 3223
"Oh, the cruft.", grep ^[^#] :-)