It is likely that you would want to categorize your JungleMail newsletters. Maybe you have some latest-news newsletters, some alert newsletters, and some general newsletters. In JungleMail you can easily categorize different newsletters using Newsletter Types. In this tutorial, you will learn how to do this.
You can enable Newsletter Types in the JungleMail Site Collection
Here you can also enable types for templates, and make this choice field required in campaign jobs.
The Channels list scope is set per site collection. This means that you should manually maintain the list of types (channels) between your site collections.
If Newsletter Types is enabled, that category choice field will appear in the Recipients tab of the Newsletter Builder.