When you create a ticket, you can enable a feature that sends an acknowledgement email to your contact. You can enable this feature and edit the email template to suit your business requirements in the Service Desk settings.
Go to the Service Desk and click on the Settings icon.

Select ‘Edit Acknowledgement E-mail Template’.

Use the composition box to edit the acknowledgement response template. You can combine text, merge codes, hyperlinks and images in the template. Once you complete the response, Click ‘OK’ to save the template.

How to insert Merge Codes
Use the drop-down list to select a Merge Code.

Move the text cursor to where to want to insert the code and click ‘INSERT MERGE CODE’.

Use the formatting icons to align the text, change the font, insert hyperlinks or images and click ‘OK’ to save.