Add Email users plugin to your WordPress website, it is one of useful plugin which does the simple job by sending Email to all registered users of your blog. You can control who will receive and who will not receive Email.
Hi, i would not recommend subscribe2, it crashed all of my website, once you install it there is no way to uninstall it, it will crash your files. I got my live site totally crashed, i had to recover from backup and then redo all the work for 2 days. You can try any other plugin.