1. Login to your webmail via http://yourdomain.com/webmail.
2. Read your mail using Horde.
3. Select the Setting Icon and go to Preferences then click on Mail on the top function as below.
4. Select Compose Templates as per below:
5. For Compose Templates mailbox , click Create Mailbox.
6. Then, select Create new Template and compose the template .
7. Click on Save Template after done.
8. Click Save to save the setting.
9. Go back to Inbox, you may found new created Templates folder.
10. You may create the template in future by go to this folder and click Use Template > Create New Template.