diff --git a/Providers/MMFCustomersGroupsServiceProvider.php b/Providers/MMFCustomersGroupsServiceProvider.php
index a1fc118..0eb10e9 100644
--- a/Providers/MMFCustomersGroupsServiceProvider.php
+++ b/Providers/MMFCustomersGroupsServiceProvider.php
@@ -9,8 +9,10 @@ namespace Modules\MMFCustomersGroups\Providers;
 use Eventy;
 use View;
 
+use Illuminate\Database\Eloquent\Collection;
 use Illuminate\Support\ServiceProvider;
 
+use Modules\MMFCustomersGroups\Entities\CustomersGroup;
 use Modules\MMFCustomersGroups\Entities\Mailbox;
 
 class MMFCustomersGroupsServiceProvider extends ServiceProvider {
@@ -97,5 +99,20 @@ class MMFCustomersGroupsServiceProvider extends ServiceProvider {
 				],
 			)->render();
 		}, 20, 3);
+
+		// Update the list of recipients if some groups have been selected.
+		Eventy::addAction('conversation.send_reply_save', function($conversation, $request) {
+			$groups = $request->groups;
+			// Return early if no group has been selected.
+			if ( empty($groups) ) return;
+			// Get the list of e-mails included in the selected groups.
+			$emails = new Collection;
+			foreach ( $groups as $group_id ) {
+				$group = CustomersGroup::find($group_id);
+				$emails->concat($group->emails());
+			}
+			$emails = $emails->unique();
+			// TODO: Update $conversation to include this list of e-mails.
+		}, 20, 2);
 	}
 }