Re: [exim] verification of Rdns

> From: Jim Pazarena
>
> I use exim to verify rdns.
> It occasionally determines a failure which I cannot 'prove'.
> Not with nslookup. not with dig.

It's why in case of empty $sender_host_name
instead of rejection I use greylisting.
More exactly, I use selective greylisting - only if something looks
suspicious. One of reasons - no RDNS or DNS failure resulting in
empty $sender_host_name .
https://github.com/Exim/exim/wiki/LenasConfig
https://github.com/Exim/exim/wiki/DbLessGreyListingRun