Also, instead of using zmprov to edit the Sieve script, use zmmailbox and the filter commands. It will also make things easily scriptable from the command line if you're adding filters in bulk
Code:
$ zmmailbox help filter
addFilterRule(afrl) [opts] {name} [*active|inactive] [any|*all] {conditions}+ {actions}+
-a/--after <arg> add after filter-name
-f/--first add as first filter rule
-l/--last add as last filter rule
-b/--before <arg> add before filter-name
deleteFilterRule(dfrl) {name}
getFilterRules(gfrl)
modifyFilterRule(mfrl) {name} [*active|inactive] [any|*all] {conditions}+ {actions}+