[CentOS] Centos 7 specific cure for Spamassassin DNS lookup problem

Thu Aug 10 13:49:32 UTC 2017
Gary Stainburn <gary at ringways.co.uk>

On Thursday 10 August 2017 09:21:31 Gary Stainburn wrote:
> I have the following error message in my /var/log/spamd
> spf: lookup failed: available_nameservers: No DNS servers available!
> Having Googled the error message I've found a number of responses which
> involve patching Perl or Spamassassin or other cures.
> Before I start changing things I was wondering if there was a Centos 7
> specific resolution. Where possible, on production machines I prefer to
> stay with RPM's rather than amending software directly.
> Also, many of these responses are over 10 years old, so I'm a little
> sceptical about their success today.

One of the solutions that I've found is to add dns_server entries into the 
config file. As this did not entail updating the software this is the option 
I've chosen.

This has fixed the original 'spf' error message, but now gives me a different 
error message. I now get one or more 

Use of uninitialized value $rr_type in string eq 
at /usr/share/perl5/vendor_perl/Mail/SpamAssassin/Plugin/AskDNS.pm line 592.

I'm now looking into this one, but any assistance would be appreciated.