Rated 5 out of 5 stars

when using autocompletion in address fields it sometimes happens, that you choose the wrong recipient. in a business environment this can be crucial, because it may happen, that you send confidential information to outsiders. using this plugin, you get warned, when you're about to send mails to recipients with a domain not in your whitelist

This review is for a previous version of the add-on (1.2.9). 

Thanks for using simple but efficient addon.