Name: jmap_querycache_max_age
Type: DURATION
Default-Value: 0m
Last-Modified: 3.6.0

The duration after which unused cached JMAP query results must be evicted
from process memory. If non-zero, then the full result of the last query
(before windowing) is stored in-memory. Subsequent queries with the same
expression and query state can then page through the cached result.  A zero
value disables query result caching.

If no unit is specified, minutes is assumed.

This feature currently only is enabled for Email/query.
