@seanbanksbliss,
In Subsicrbe2->Settings under the Template tag you can change the email notification template to suit your site and audience. On that page you will see several KEYWORDS listed that subscribe2 replaces with content from your posts for example.
Some of these keywords are only use in one of the possible email types, so some only work in per-post notification and some only work in digest notifications.
That error message is telling you that your template contains some keywords that will not work in your chosen email type, so you need to amend the template.
[EDIT] – post before you edited the thread ??