As a customer, in the customer notification emails I'd like to see the full comment history for my issue

Right now customer notification emails can only contain the latest comment, and only for comment added and comment edited notifications. Our customers don't log into JIRA, so these comments are often hard to understand because without the full chain of comments they're out of context.

Our customer notification templates look like this:

${event.user.name} commented:

${comment}

Perhaps a solution would be to have a variable for all comments? E.g.,

${event.user.name} commented:

${issue.comments}

We're using Service Desk 3.5.0 and JIRA 7.3.6.

If there's a way of doing this already then please let me know.