Boone Gorges

CUNY Academic Commons

This plugin adds two widgets to your WordPress MU/BuddyPress installation: Groups and Members. Use them instead of the Groups and Members widgets that ship with BuddyPress. They provide the ability to select which of the three tabs – Newest, Active, or Popular – will be the widget’s default view.
Version 0.2 of this plugin works only with BuddyPress 1.2. For earlier versions of BuddyPress, please download version 0.1 of the plugin.
Developed for the CUNY Academic Commons. Visit http://commons.gc.cuny.edu to learn more about this Totally Kewl project.

Enhanced BuddyPress Widgets

Provides enhanced version of BuddyPress's core Groups and Members widgets

alexhal

Allows Buddypress group Mods to send email to all group members from group admin/manage section. 
To enable E-mail members for mods simply put the code given below in your bp-groups-members-mail.php file in the end from wp-admin-> plugins-> editor :
<pre><code>add_filter('gmm_enable_for_mods','gmm_enabled_for_mods');
function gmm_enabled_for_mods(){
 return true;
}
</code></pre>
By default this “E-Mail Members” section is available to mods and admin . 
To change it a filter is available and you can change the access like this : 
To restrict this option to admins only 
 add_filter(‘bp_gmm_auhority’,function(){ 
 return ‘admin’; 
 });

Group Members Mail Plugin

I've done a quick test and it worked with no problems for unformatted email

Does what it says on the tin!

Allows Buddypress group Mods to send email to all group members .

Enhanced BuddyPress Widgets vs Group Members Mail Plugin