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

On 08/10/2017 01:21 AM, Gary Stainburn wrote:
> I have the following error message in my /var/log/spamd
>
> spf: lookup failed: available_nameservers: No DNS servers available!


Try starting spamassassin later.  Run "systemctl edit 
spamassassin.service" and insert two lines:

[Unit]
After=network-online.target