wp-snpn
This WordPress plugin add a checkbox in your post editor to send an email to the email address of your choice when the post is published.
You can configure if the email is sent to all members of the website, or to an specific email address (to use a Mailing List for example).
Actually, this plugin doesn't have any support. Use it at your own risks. I want to add new functionnalities (like choosing member roles for the mailing list) before proposing any support.