scribu

Scenario
You’re the only user who can create posts and moderate comments on your WordPress installation.
You have both ‘Email me when anyone posts a comment’ and ‘Email me when a comment is held for moderation’ options checked.
You get an email about a comment awaiting moderation and you approve it.
The problem is that right after that you get a second email letting you know that a new comment has been posted, which of course you already knew about.
Solution
Instead of disabling email notifications for new comments alltogether, you can use this plugin and not receive the redundant emails mentioned above.
Links: <a href="http://scribu.net/wordpress/filter-email-notifications" rel="nofollow ugc">Plugin News</a> | <a href="http://scribu.net" rel="nofollow ugc">Author’s Site</a>

Filter Email Notifications

Stop WordPress from sending email notifications for comments that have been manually approved.

curoagency

WooCommerce sends an email to the store admin every time an item is placed on backorder. There is no built-in toggle to disable this — the only options in WooCommerce → Settings → Emails control the email template, not whether it sends at all.
This plugin removes that notification cleanly, with no options page and no bloat.
What it does:
<ul>
<li>Prevents the “Product Backorder” admin notification email from being sent</li>
<li>Has no effect on any other WooCommerce emails</li>
<li>Does not affect the customer’s order confirmation or any other customer-facing emails</li>
<li>Works automatically on activation — no configuration required</li>
</ul>
Who is this for?
Store owners who use backorders as a standard fulfilment method and find the admin notification emails unnecessary or disruptive. If your warehouse team or fulfilment process handles backorders without needing an email trigger, this plugin removes the noise.

Disable WooCommerce Backorder Emails

Stops WooCommerce from sending backorder notification emails to the admin. No settings needed — just activate and it works.

Filter Email Notifications vs Disable WooCommerce Backorder Emails