The Message module provides a user interface for configuration at /admin/config/system/message. There are three main areas of configuration. First, you can set an expiry date on messages so that messages older than a certain number of days are purged from the database. Second, there is a utility for copying text fields from one language to another (see second screenshot below). This makes it easier to create multilingual message text fields. Third, you can use the DrupalQueue for batch processing (and deleting) messages that do not have a reference to another entity.