Index: src/bp-core/deprecated/2.2.php
--- src/bp-core/deprecated/2.2.php
+++ src/bp-core/deprecated/2.2.php
@@ -104,3 +104,13 @@
 function bp_core_add_global_group() {
 	_deprecated_function( __FUNCTION__, '2.2', 'This function has no replacement' );
 }
+
+/**
+ * Add a piece of message metadata.
+ *
+ * @deprecated BuddyPress (2.3.0)
+ */
+function bp_message_add_meta( $message_id, $meta_key, $meta_value, $unique = false ) {
+	_deprecated_function( __FUNCTION__, '2.3.0', 'bp_messages_add_meta()' );
+	return bp_messages_add_meta( $message_id, $meta_key, $meta_value, $unique );
+}

Index: src/bp-messages/bp-messages-functions.php
--- src/bp-messages/bp-messages-functions.php
+++ src/bp-messages/bp-messages-functions.php
@@ -443,7 +443,7 @@
  *
  * @see add_metadata() for full documentation excluding $meta_type variable.
  */
-function bp_message_add_meta( $message_id, $meta_key, $meta_value, $unique = false ) {
+function bp_messages_add_meta( $message_id, $meta_key, $meta_value, $unique = false ) {
 	add_filter( 'query', 'bp_filter_metaid_column_name' );
 	$retval = add_metadata( 'message', $message_id, $meta_key, $meta_value, $unique );
 	remove_filter( 'query', 'bp_filter_metaid_column_name' );