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.

xwebyna

<h3>Admin Post Notifier</h3>
Always want to be notified when any of your blog contributors submit a new post? If yes, the gaol of Admin Post Notifier is to deliver emails to the site admin when there is a new (or updated) pending post for review.
No additional setting is required of you. The plugin utilizes the WordPress core email functionality to send email notifications when activated.

Admin Post Notifier

This is a simple plugin that sends email notification for every new post submitted for review.

Filter Email Notifications vs Admin Post Notifier