How CD event queue knows about Master in WFFM approval? 8.2

CD should not be knowing about Master as CD has Web database. But in WFFM sometimes we need to approve something (eg: public review on a public site). This approval should go to Master for the content publisher to approve.

earlier( before 8.0) we had remoteWfmService connectionstring. But now(using 8.2.3) we have event queues. So how does event queue learn about Master DB? My answers and confusion is given below.

1. Enabling /App_Config/Include/ScalabilitySettings.config and providing publishing.publishingInstance setting with machinename-IISinstance of CMS. Correct?
2. But is eventqueue enabled just by enabling a config? I mean there is no EnableEventQueues settings(switch/toggle) in 8.2.3.
3. If the above file is not enabled then from webconfig (but where? )
4. Any other place?

As you already mentioned the Event Queue is Used by WFFM.

On scaled environments where the content delivery servers have no access to the master database. You need something to transfer the form field values to the CMS server for processing the remote save actions on the CMS server. Since Sitecore Web Forms for Marketers 8.0 rev.150224 (Update-2) The Sitecore EventQueue is used, on older versions the "remoteWfmService" web-service is used.

It is about the EventQueue SQL database table from the Sitecore Core database.

It is important that the CM uses the same core database as the CD. Or sync at least the EventQueue table. You can easily recognize the WFFM records on the EventType.

For Sitecore 8.1 I did not find a way to easily customize the event queue mechanism. I assume same for 8.2

See also: http://sitecore.stockpick.nl/english/wffm-and-secure-fields/ for more details of the data submit flow.