The majority of your emails will be delivered using campaigns and workflows, but there are a few emails that are managed within the modules that they are a part of. They tend to be more transactional emails but are still customizable. Let's take a look at which emails you'll want to manage within the modules:

When you click into each of your applications, at the bottom of the left navigation menu, you'll see Autoresponder Messages.

Each message in here can be customized, toggled on and off, and will serve as the primary driver for transactional messages delivered from actions taken on your application.

Additionally, by clicking into them, you are able to add text messages to each of these notifications.

Similarly, on events, there are transactional emails that can be managed.  Initially, there are two, but you can add more for each event. Click on the event, click Signups, and click Messages.  You can define the channel, toggle them on and off, edit them, and create new event driven emails here as well.

One unique part of using the communications in events is that you can send event specific emails based on timing of that specific event very easily and also pull in event specific tokens.

Keep in mind that aside from the messages discussed here, all communications will need to be built within the Campaigns, Workflows, and Rules modules.