I want to change the look and feel of the emails we send our customers. Can I edit or create placeholders in the email template?
The placeholders in an email template are system defaults, and it's not possible to create a new one or edit the contents of an existing one. However, there are a few different ways to achieve what you might be looking for:
Formatting placeholders with liquid markup
By using liquid markup to format placeholders, you can change the look and feel of your emails. For more information, see this article: How can I format placeholders with Liquid markup?
Modifying your triggers
Instead of managing how your messages look on the template level, you can make modifications for each kind of email you send out by navigating to the different triggers that send these messages. For instance, the email you automatically send to customers when they log a new request can be formatted (either with plan text or HTML) differently than the email that reminds customers that they haven't responded to your last message.
See these resources for more information: