You get an email daily if there is some difference between WordPress.org’s Changelog page and readme.txt in SVN trunk.
After activation a “Watch” link is added to each plugin. You may add there a plugin to watch for changelog differences. After clicking on “Watch” it toggles to Unwatch and vice versa.
The daily (wp-cron) cycle begins when you activate the plugin. The email is sent to the admin email address with subject [<plugin-name>] Changelog mismatch.
The email’s body is the first line (the latest release listed) of the SVN version and the WordPress.org Changelog page. You can write to plugins AT wordpress.org to correct the problem or wait for your next release.