For SpamAssassin and anti-spam updates
ZCS 8.0.5 and later
For ZCS 8.0.5 and later, SpamAssassin scans for all *.cf files in /opt/zimbra/conf/sa and loads them in alphabetical order. If you create a sausers.cf file, it will be loaded after salocal.cf is loaded. This is the supported method for doing customizations of SpamAssassin.
ZCS 7.2.5 and later
For ZCS 7.2.5 and later, SpamAssassin customizations go in /opt/zimbra/conf/sauser.cf. On upgrade from ZCS7 to ZCS8, that file gets moved to /opt/zimbra/conf/ca
amavisd.conf.in:$sa_userprefs_file = '/opt/zimbra/conf/sauser.cf'; </quote>
Customizing Postfix using the "zmprov ms ..." method survives upgrades. On plain (non-Zimbra) Postfix servers, it is helpful to use certain Postfix restrictions not configurable via the Zimbra Admin Console. It is both permissible and the recommended way now to perform such customizations, for example:
zmprov ms <server> +zimbraMtaRestriction reject_unknown_reverse_client_hostname