title: Proxmox Mail Gateway: Postfix Queue
agents: pmg
catalog: app/pmg
license: GPLv2
distribution: check_mk
description:
 Monitors the depth of each Postfix mail queue (deferred, active,
 incoming, hold) via {/nodes/{node}/postfix/queue/{queue}}. A growing
 "deferred" queue usually means downstream delivery is failing (DNS,
 greylisting, a full-disk target, or a blocked relay); a growing
 "hold" queue means messages are stuck due to policy/content-filter
 action.

 WARN/CRIT thresholds are configurable per queue via the ruleset
 "PMG Postfix queue depth".

item:
 The queue name: {deferred}, {active}, {incoming}, or {hold}.

discovery:
 One service per queue name is created.
