I found the solution in the supplementary documentation here:
Supergeekery - CraftCMS HTML Email Template Missing Documentation
In Craft CMS 5, you can indeed override the default system messages without modifying them directly in the Control Panel or database. Instead of relying on the content from /admin/utilities/system-messages, you can customize the email templates by switching based on the email type (emailKey).
To do this, add the following switch block to your email template:
{% switch emailKey %} {% case "account_activation" %} <p>{{ "You're activating your email." | t }}</p> {% case "verify_new_email" %} <p>{{ "Let's verify your new email address." | t }}</p> {% case "forgot_password" %} <p>{{ "Don't worry, we'll reset that password now." | t }}</p> {% case "test_email" %} <p>{{ "Testing makes perfect." | t }}</p> {% default %} {{ body }} {% endswitch %} {{ body }}
However, instead of hardcoding the text like this, you can include the templates you've already created in your /templates/email/ folder:
{% switch emailKey %} {% case "account_activation" %} {% include "email/account-activation.twig" %} {% case "verify_new_email" %} {% include "email/email-verification.twig" %} {% case "forgot_password" %} {% include "email/password-reset.twig" %} {% case "test_email" %} {% include "email/test-email.twig" %} {% default %} {{ body}} {% endswitch %} {{ body }}
This approach allows you to fully customize the content of system messages outside of the database by utilizing template files, and it also supports multi-language setups.
