Custom fields not resolving in email

I have serveral custom fields defined in a template.
Example COMPANY.

In the post-install, this resolves to ${VIRTUALSERVER_FIELD_COMPANY} and is set correctly.

However, when I try to use it in the email sent to domain owners, neither ${VIRTUALSERVER_FIELD_COMPANY} nor ${COMPANY} resolve.

What's printed in the email is either:
${VIRTUALSERVER_FIELD_COMPANY} or ${COMPANY} (lteral)

How does one get custom fields to expand in emails? This is important for distributing/notifying about license keys and what not.