Editing email templates
You can use placeholders in email templates. Learn more
You have complete control over the way emails look when someone updates a ticket or adds a reply to it.
To edit the template go to Settings > TICKETS > Settings page.
Scroll down to Email Templates.
You'll find the HTML Template there.
Please make sure you keep the opening and closing <body> tags and {$content} placeholder.
When a trigger needs to send an email, the HTML Template is loaded and the {$content} placeholder is replaced with the email template of the trigger.
If you wish to edit specific notifications, refer to this guide: Editing ticket notifications
You might want to check that the template doesn't contain any errors before saving it. Try checking it using HTML Email Check and Validation Tool (3rd party service).