checkbox values do not show up in emails

[kbrown]

I've got a new multipage api formset up on the same site I already have a couple simpler forms working properly on.

Everything with this new form seems to work with the exception that any value that was set via a checkbox doesn't show up in the emails or email tests. The form is all text fields and checkboxes and only the checkboxes have this problem. The checkboxes values show up with proper display values and everything in the database. The email template seems to have the proper markup but every time there is a {$ANSWER_checkbox_response_placeholder} it doesn't show up.

Could the problem be in my form markup? Here is an example of how I'm doing the checkboxes:
<label><input type="checkbox" name="contact_by_phone" value="Phone" /> Phone</label>
<label><input type="checkbox" name="contact_by_email" value="Email" /> Email</label><br />

[mrGarvin]

One quick guess is that the email content doesn't contain these fields. Maybe you did changes to the structure AFTER you set up your email?

What's in your email content?
There should be lines like this:
{$QUESTION_contact_by_phone} {$ANSWER_contact_by_phone}