how to add a new email template in campaign

Summary:

Content (please ensure you mask any confidential information):

Hello,

We want to add a new email template format in the campaigns, so that whenever recruiter want to send out a particular mailer they all can sent it out in a single format after selecting the template.

Is this possible ? If so how do to this ?

Version (include the version you are using, if applicable):

23d

Code Snippet (add any code snippets that support your topic, if applicable):