Re: Proper ACL condition to block failed rDNS lookup

Ahoj,

Dňa Sat, 7 Jun 2025 23:44:50 -0700 AC via Exim-users
<[email protected]> napísal:

> Because according to the documentation that variable is set if it's
> more than just no rDNS but also a mismatch with a forward DNS query.
> Unless I'm misreading the below documentation this is not what I'm
> asking for.

IMO, the main problem with built-in exim's PTR check is, that it does
full FCrDNS, thus both of $host_lookup_deferred & $host_lookup_failed
can refer to DNS problem with both, the PTR or A/AAAA lookup, without
distinguishing them.

If one is interested in PTR only, (s)he need to do DNS lookup by self:

    ${lookup
    dnsdb{defer_never,retrans_1s,retry_2,ptr=$sender_host_address}}

Set that into $acl_c_... variable and then check if variable is empty...

regards

-- 
Slavko
https://www.slavino.sk

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