CRM gives you multiple ways to create emails and send them. This article will cover the places you can create email messages.
System Email Templates
Users can create email templates that are available to all other users. The templates can be used in Quick Campaigns, individual messages, or workflows. The benefit to system email templates is that the can be used by any user. However, they can also be edited by any user and the changes take effect immediately. These are ideal for messages that are fairly generic, that are used frequently, or that don't change often. CRM will come with default templates already created that you can edit.
Create System Email Templates in Settings > Templates > Email Templates
When creating a new system email template pay attention to template type.
Template type allows you to access specific merge fields from a particular entity and can be used to filter templates when adding them to a quick campaign or a work. Global templates are not tied to any one entity, all others are clearly labeled with the originating entity name.
Personal Email Templates
Personal email templates work the same way as system email templates, but they are only accessible to the user who creates them. These are useful if you send out a message regularly that others do not send. The benefit to these is that you can be more personal in your style and that other users cannot edit the templates.
Create an Email within a Workflow
While templates can be used in workflows, you may find that you want to create the email within the workflow itself. When an email is part of a workflow it cannot be sent out in any other way. To edit emails within a workflow you must disable the workflow first and then activate it when you are done. Workflow emails do have a little more flexibility in adding merge text from the entity that triggers the workflow and related entities.