In-Memory Processing

ListManager can send one-off messages directly in memory without using the outgoing mail queue.

The benefit of this approach is that by sending one-off messages in memory, rather than through the outgoing mail queue, you save the extra work of writing and reading the message to disk and you also slow the growth rate of the outgoing mail database table.

The downside to In-Memory processing is that you cannot view sent one-off messages in the "outgoing mail" page of the web interface. If you disable the In-Memory processing feature, you will be able to view sent one-off messages in the "outgoing mail" page of the web interface.

We recommend that most sites disable In-Memory process and set the “clean outgoing mail queue” option to be a small number, such as 5.