A newsletter campaign is a planned mass mailing of specific content to a defined group of subscribers. The `/newsletter-job` module serves to allow the operator to prepare, launch, monitor its progress in real-time, and subsequently evaluate how it performed. The campaign differs from a one-time transactional email primarily in that it runs in batches with speed limits — only a certain number of messages are sent each minute — to prevent blocking by mail servers and to ensure that the deliverability of other messages from the given domain does not decrease. The module builds upon **Newsletter** as a source of subscribers and **Emails...**
