Email Alert When a User's Role Changes
Emails the site administrator whenever a user's role changes, which helps spot unexpected privilege changes.
Snippet Library
Email snippets for WordPress
Snippets for the emails WordPress sends: change the sender name and address, add a Reply-To header, send HTML email and turn off notifications you do not need. For site owners who want their messages to arrive and look right.
Log Failed Emails
Writes a line to the PHP error log whenever wp_mail() fails, with the subject, recipients and error message, to help debug delivery problems.