Quarantine Area: Stores messages that you would like to analyze before deciding whether to delete or release to the intended recipient(s).

Archive Area: Stores messages for future reference.

Postponed Queue: Stores messages that will be delivered at a specified time.

MTA Queues: Store messages in four types of MTA queues: Incoming, Active, Deferred and Hold. The Incoming queue stores messages that just arrived at IMSVA; the Active queue stores messages ready to be delivered to the next MTA; the Deferred queue stores messages deferred due to delivery failure; the Hold queue stores messages kept on hold for later manual delivery.

There are 4 values to control IMSVA (postfix) retries. For more information, see Deferred Queue Parameters.

For one deferred email message, the lifetime is 24 hours, the first retry attempt is after 15 minutes, the second retry is after 30 minutes, and all subsequent retries are after 60 minutes. That means there are about 25 retries before the maximal_queue_lifetime value is reached.

Virtual Analyzer Queue: Stores messages that IMSVA submits to Virtual Analyzer before IMSVA receives message analysis results.