Re: [exim] host lookup deferred for reverse lookup check

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Author: Casey Allen Shobe
Date:  
To: exim-users
CC: bclark
Old-Topics: [exim] host lookup deferred for reverse lookup check
Subject: Re: [exim] host lookup deferred for reverse lookup check
On Friday 03 March 2006 11:56, bclark wrote:
> Hi all
>
> I was busy scanning my reject logs, and I came across this
>
> 2006-03-03 12:47:51 H=(resweb) [196.25.20.98]
> F=<contactus@???> temporarily rejected RCPT
> <bclark@???>: host lookup deferred for reverse lookup check
> For the middle paragraph (sender verification), Is is possible to tell it
> to skip this test for a list of ipaddress.

[...]
> Although, I believe this does not solve / answer the original question /
> problem cause obviously the Admin for proteahotels.com was to lazy to add a
> reverse lookup record.
>
> I need to find away to allow the emails.


Well, better a late reply than never. This is what I do, which allows me to
keep a list of IPs that are allowed to skip the reverse DNS requirement
(though I try to keep this as a temporary measure, and get in touch with the
legitimate companies that lack reverse DNS):

acl_check_helo:
[...]
        accept  hosts           = +known_mailhosts
        warn    !verify         = reverse_host_lookup
                set acl_c9      = reject_predata=yes $acl_c9
                set acl_c8      = Please see 
http://help.seattleserver.com/?page=email_reverse_dns - Reverse DNS records 
are required for sending mail servers, but your mail server, 
$sender_host_address, does not have one!
                log_message     = HELO (deny in PREDATA): No reverse DNS 
record present for $sender_host_address (claimed to be $sender_helo_name).
[...]
acl_check_predata:
        deny    condition       = ${extract{reject_predata}{$acl_m9}{$value}
{no}}
                message         = $acl_m8
                log_message     = PREDATA (deny): Rejected due to prior 
setting ($acl_m8).
                set acl_m0      = ${lookup 
pgsql{select "statistics_reverse_dns_insert" ('${quote_pgsql:
${recipients}}', '${quote_pgsql:${sender_address}}', '${quote_pgsql:
${sender_rcvhost}}')} {$value}fail}
        accept


Here it is in context if you're interested:
http://test.seattleserver.com/conf/exim/exim.conf.primary_mx

--
Casey Allen Shobe | cshobe@??? | 206-381-2800
SeattleServer.com, Inc. | http://www.seattleserver.com