Many thanks for all the replies. Appreciated!
> make sure to configure your milter to ignore connections from
127.0.0.0/8
This was the reply that did it. It spurred me to investigate the
/etc/default/spamass-milter config, wherein I had...
OPTIONS="-u spamass-milter -- -d 127.0.0.1"
On looking closer, and with the aid of online searches, I amended it to...
OPTIONS="-u spamass-milter -- -i 127.0.0.1"
which seems to work fine.
I've now noticed a similar problem with clamav / clamav-milter, for
which I'm still searching for a solution.
