2. Within the new message composition window, click Office Add-Ins in the top right hand corner of the ribbon.

3. This will open a window with a list of the add-ins currently available to you. Double-click My Templates to open the add-in.

4. The My Templates add-in will appear on the left hand side of your message composition window, with three templates are available by default. Select one to insert specific text into the body of your message. For example, if you select I'll reply later, the message "Heading to a meeting. I'll get back to you soon." will be included in the email message you're writing. To add a template to the My Templates add-in, select the '+ Template' button.

5.Type a title for the template and the text you want to have inserted in your email, and then select Save. To format the text of a template, it is recommended that you type your message in the body of a new email, apply desired formatting, then copy and paste. 

7. To edit the text in a template, select Edit, add or modify text as needed, and then select Save. To delete a template, select the Trash icon next to the template you want to delete. The template is deleted immediately, and there is no undo option.