Sam Hoe

Email Alert subscribe form. You can manage through the admin pages of your blog. Simple put the shortcode ‘[sh_email_alert_form]’ into your page or post.

SH Email Alert

WP BackOffice

Enable user to share their invoices with as many email address as they like, all from the order review and view order pages. Simply install the plugin, customize your messages and that’s it.
Features:
<ul>
<li>Simple installation makes getting started easy.</li>
<li>Customize all form field values, error messages and the page/position the form is displayed on.</li>
<li>Edit the email template under WooCommerce’s email settings from full integration with WooCommerce.</li>
<li>Validates users to prevent unauthorized usage.</li>
<li>Easily customize email subject</li>
<li>Uses default WooCommerce Order Template</li>
</ul>
<a href="http://www.wpbackoffice.com/plugins/woocommerce-invoice-sharing" rel="nofollow ugc">Plugin’s Official Documentation and Support Page</a>

WooCommerce Invoice Sharing

Enable user to share their invoices with as many email address as they like, all from the order review and view order pages.

SH Email Alert vs WooCommerce Invoice Sharing