Theming inconsistencies

Problem/Motivation

The module is attempting to run the templates through a non-existent theme function, which has been causing some inconsistencies in how email ends up being rendered. We need to change this to just send raw, as that is probably what will be most useful in the most cases. Users will still have the opportunity to alter it in custom code if they require.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes