gistfile1.xml

    <!-- EMAIL CONFIG -->
    <email_settings>
        <recipients to="point_to_field:subject" cc="" bcc="" />
        <smtp auth="yes" host="" username="" password="" secure_type="tls" port="587" />
        <subject>Someone is getting in touch with you!</subject>
    </email_settings>

    <!-- FIELDS SETTINGS -->
    <fields>
        <new_radio_list name="subject" label="Subject: ">
            <options>
                <option email="[email protected]">General</option>
                <option email="[email protected]">Sales</option>
                <option email="[email protected]">Complain</option>
            </options>
            <validation>
                <required>Please, choose a subject.</required>
            </validation>
        </new_radio_list>
    </fields>