Step One - Create a URL Target
By creating a URL target as below (settings/extensions/add target/URL target) this will allow you to set a trigger to carry out a certain action upon the ticket that the trigger or automation ran on.
Attribute name: ticket[comment][body]
Save the URL Target to something like "Auto Private Comment" and then you can use it as a target using the NOTIFICATIONS: Target trigger option.
Step Two - Create the trigger
Now set up your trigger or automation with your relevant trigger options. In the 'actions' section you can select the 'notifications: Notify Target' option and select the target you created in step one.
Next, add the comment you want to be posted for example:
CUSTOMER HAS RECEIVED 24 HOUR NOTIFICATION EMAIL.
<p>We just wanted to see if you have had time to take a look at our recent email? We haven’t heard back from you and wanted to make sure we hadn’t missed you.</p>
<p>If you want to get in touch with any questions or comments you may have when you get a moment, or if you want to let us know if you need a little more time to digest the information, just hit reply. </p>
This comment will now be added as a private comment whenever the trigger actions run.
It's excellent for setting reminders for agents who aren't using email much as it will reopen in their views. And also good for keeping track of automated messages sent to customers without needing to interpret the 'events' section of the ticket view.