ensure valid hostname for amavis on centos

Author: Florian Schaal

install/tpl/fedora_amavisd_conf.master

@@ -144,7 +144,7 @@ $defang_by_ccat{+CC_BADH.",6"} = 1;  # header field syntax error
 
 # OTHER MORE COMMON SETTINGS (defaults may suffice):
 
-# $myhostname = 'host.example.com';  # must be a fully-qualified domain name!
+$myhostname = '{hostname}';
 
 $notify_method  = 'smtp:[127.0.0.1]:10027';
 $forward_method = 'smtp:[127.0.0.1]:10025';  # set to undef with milter!