diff --git src/bp-templates/bp-nouveau/includes/groups/ajax.php src/bp-templates/bp-nouveau/includes/groups/ajax.php
index c11df9d2e..9714f81a8 100644
--- src/bp-templates/bp-nouveau/includes/groups/ajax.php
+++ src/bp-templates/bp-nouveau/includes/groups/ajax.php
@@ -394,7 +394,7 @@ function bp_nouveau_ajax_send_group_invites() {
 	if ( ! empty( $_POST['message'] ) ) {
 		$bp->groups->invites_message = wp_kses( wp_unslash( $_POST['message'] ), array() );
 
-		add_filter( 'groups_notification_group_invites_message', 'bp_nouveau_groups_invites_custom_message', 10, 1 );
+		add_filter( 'bp_email_set_post_object', 'bp_nouveau_groups_invites_custom_message', 10, 2 );
 	}
 
 	// Send the invites.
@@ -403,7 +403,7 @@ function bp_nouveau_ajax_send_group_invites() {
 	if ( ! empty( $_POST['message'] ) ) {
 		unset( $bp->groups->invites_message );
 
-		remove_filter( 'groups_notification_group_invites_message', 'bp_nouveau_groups_invites_custom_message', 10, 1 );
+		remove_filter( 'bp_email_set_post_object', 'bp_nouveau_groups_invites_custom_message', 10, 2 );
 	}
 
 	if ( array_search( false, $invited ) ) {
diff --git src/bp-templates/bp-nouveau/includes/groups/functions.php src/bp-templates/bp-nouveau/includes/groups/functions.php
index cf85567dc..bf59fd239 100644
--- src/bp-templates/bp-nouveau/includes/groups/functions.php
+++ src/bp-templates/bp-nouveau/includes/groups/functions.php
@@ -349,26 +349,30 @@ function bp_nouveau_group_setup_nav() {
 }
 
 /**
- * @since 3.0.0
+ * Append the Group Invites message to the email sent.
+ *
+ * @since 3.0.0 Filters 'groups_notification_group_invites_message'
+ * @since 3.0.1 Filters 'bp_email_set_post_object' instead of the deprecated
+ *                      'groups_notification_group_invites_message' filter.
+ *
+ * @param  WP_Post  $post  The post object containing html & plain email text.
+ * @param  BP_Email $email The email (object) about to be sent.
+ * @return WP_Post         The post object containing html & plain email text.
  */
-function bp_nouveau_groups_invites_custom_message( $message = '' ) {
-	if ( empty( $message ) ) {
-		return $message;
-	}
-
+function bp_nouveau_groups_invites_custom_message( WP_Post $post, BP_Email $email ) {
 	$bp = buddypress();
 
-	if ( empty( $bp->groups->invites_message ) ) {
-		return $message;
+	if ( empty( $bp->groups->invites_message ) || ! $post->ID ) {
+		return $post;
 	}
 
-	$message = str_replace( '---------------------', "
----------------------\n
-" . $bp->groups->invites_message . "\n
----------------------
-	", $message );
+	$message = wp_strip_all_tags( $bp->groups->invites_message );
 
-	return $message;
+	// Edit the rich and plain text email contents.
+	$post->post_content .= "\n" . $message;
+	$post->post_excerpt .= "\n\n" . $message;
+
+	return $post;
 }
 
 /**