For a site with 50 + users, I’m using the Subscribe2 plugin to send mail out to the group using WP. I’ve created a category called Mail and updated everyone’s Subscribe2 preferences to get updates when the Mail category is updated. Voila, email to the group!
Here’s a help video that walks through how it works. The video also shows some basic tips for using WP.






That worked, but people were still getting emails 2 and 3 times. I’ve lowered the bar and now I’m using Mailman (http://www.gnu.org/software/mailman/index.html).
this tutorial honestly helped me out a lot with wordpress, as i am a beginner.