Email notifications in Targetprocess are flexible and can be customized. It is possible to modify templates for notifications configured in Process Workflow settings and for some predefined system events as well. Templates that can be modified include:

User AddedSent when a user account is added to Targetprocess.
Attachment CreatedSent when an attachment is added to a particular entity.
Comment CreatedSent when a comment is added to an entity.
Entity AssignedSent when a user is assigned to a particular entity.
Entity ConvertedSent when an entity’s type has been changed through conversion.
Entity CreatedSent when an entity is added.
Entity State ChangedSent when an entity changes state.
Forgot PasswordSent when a user requests a password reset from the login form.
Auto Reply to RequestersSent to requesters when their email requests are accepted. More details: How to setup auto reply to requesters.
Service Desk Password ChangedSent when a user is registered to service desk and to Activate account or Update password.
View Access NotificationSent to user with whom the view has been shared to.
Mention CreatedSent when a user is been mentioned in a comment.
User RestoredSent to the user when he/she has been restored back.

More information on different kinds of email notifications can be found here: Notifications

Find how to access templates editor pages here: How to change an email notification template.