Seems a growing number of unwanted email are using "<various>@localhost.localdomain" as the sender.

Looking at the history of this host file entry, it seems it is largely in /etc/hosts for the purposes of making sure that things that derive the domain name from the hostname, get something back. Nothing should do that now (afaik), however I just specifically excluded it in a Postfix access table, as the smallest change that should stop the junk.

With apologies to Gumtree who seem to use this in their sending script (time to fix the code guys), I doubt they are alone, I just hope I'm not doing it anywhere crucial.