if template is UNSPECIFIED:

            template = self.config.get('rattail.mail', '{}.subject'.format(self.key),

                                       default=self.default_subject)

            if not template:

                template = self.config.get('rattail.mail', 'default.subject')

        if template and render:

            return Template(template).render(**data)

        return template

    def get_complete_subject(self, data={}, render=True, prefix=UNSPECIFIED, template=UNSPECIFIED):

        """

        Returns the value for the message's ``Subject:`` header, i.e. the base

        subject with the prefix applied.  Note that config may provide the

        complete subject also, in which case the prefix and base subject are

        not considered.

        :rtype: str

        """

        if prefix is UNSPECIFIED:

            prefix = self.get_prefix(data)

        prefix = (prefix or "").rstrip()

        if prefix:

            prefix = "{} ".format(prefix)

        return "{}{}".format(prefix, self.get_subject(data, render=render, template=template))

    def get_template(self, type_):

        """

        Locate and return the Mako email template of the given type

        (e.g. 'html'), or ``None`` if no such template can be found.

        """

        try:

            return self.templates.get_template('{0}.{1}.mako'.format(self.key, type_))

        except TopLevelLookupException:

            if self.fallback_key:

                try:

                    return self.templates.get_template('{0}.{1}.mako'.format(self.fallback_key, type_))

                except TopLevelLookupException:

                    pass

    def normalize_attachments(self, attachments):

        normalized = []

        for attachment in attachments:

            if isinstance(attachment, six.string_types):

                attachment = self.normalize_attachment(attachment)

            normalized.append(attachment)

        return normalized

    ATTACHMENT_MIME_MAP = {

        '.pdf': 'pdf',

        '.xls': 'vnd.ms-excel',

    }

    def normalize_attachment(self, path):

        root, ext = os.path.splitext(path)

        ext = ext.lower()

        if ext == '.csv':

            with open(path, 'rb') as f:

                part = MIMEText(f.read(), 'csv', 'utf_8')

            filename = os.path.basename(path)

            part.add_header('Content-Disposition', 'attachment; filename="{}"'.format(filename))

            return part

        else:

            mimetype = self.ATTACHMENT_MIME_MAP.get(ext)

            if mimetype:

                with open(path, 'rb') as f:

                    part = MIMEApplication(f.read(), mimetype)

                filename = os.path.basename(path)

                part.add_header('Content-Disposition', 'attachment; filename="{}"'.format(filename))

                return part

        raise ValueError("Magic is not (yet) supported, please construct your own attachments for file: {}".format(path))

    def make_message(self, data={}, attachments=[], inlines=[],

                     subject_prefix=UNSPECIFIED, subject_template=UNSPECIFIED,

                     sender=UNSPECIFIED, replyto=UNSPECIFIED,

                     to=UNSPECIFIED, cc=UNSPECIFIED, bcc=UNSPECIFIED):

        """

        Returns a proper email ``Message`` instance which may be sent via SMTP.

        """

        txt_template = self.get_template('txt')

        html_template = self.get_template('html')

        attachments = self.normalize_attachments(attachments)

        # TODO: provide more defaults?

        data.setdefault('six', six)

        if txt_template and html_template:

            txt_part = MIMEText(txt_template.render(**data), _charset='utf_8')

            html_part = MIMEText(html_template.render(**data), _subtype='html', _charset='utf_8')

            if inlines:

                html_part = MIMEMultipart(_subtype='related', _subparts=[html_part] + inlines)

            msg = MIMEMultipart(_subtype='alternative', _subparts=[txt_part, html_part])

            if attachments:

                msg = MIMEMultipart(_subtype='mixed', _subparts=[msg] + attachments)