* +config.action_mailer.default_implicit_parts_order+ - When a message is built implicitly (i.e. multiple parts are assembled from templates
which specify the content type in their filenames) this variable controls how the parts are ordered. Defaults to +["text/html", "text/enriched", "text/plain"]+. Items that appear first in the array have higher priority in the mail client
and appear last in the mime encoded message.
h4. Configuring Active Resource
There is a single configuration setting available on +config.active_resource+: