Sendgo

Easily lets you create a bar on top or bottom to display a notification.

This plugin performs a simple task of disabling email notifications that are sent by WordPress when a plugin or theme auto-updates.

Supercharge your WordPress email notifications using a WYSIWYG editor and shortcodes. Default and new notifications available. Add-ons available.

Sends email to notify you if there are any updates for your WordPress site. Can notify about core, plugin and theme updates.

Show a waitlist form on out-of-stock products and automatically email subscribers when items are restocked. Turn lost sales into customers.

Simply the easiest way to add a topbar to your website. Create a notification bar in no-time and show a message and a button to your visitors.