What option allows moderators to review all messages that are sent to a distribution list?

Message moderation is the correct option as it specifically enables a designated person or group, known as moderators, to review messages sent to a distribution list prior to those messages being delivered to the members of that list. This process allows moderators to manage the content and ensure that only appropriate messages are approved for distribution, maintaining control over the communication within the group.

In the context of distribution lists, message moderation serves as a valuable tool in preventing spam or inappropriate content from reaching members, thereby enhancing the quality of the conversations taking place.

The other options do not serve this function; for instance, message filters relate to the automatic handling of incoming messages based on specific criteria, but they do not involve human oversight. Content approval typically refers to a process that ensures information meets certain standards before publication, but it is not specifically about moderating distribution list messages. Mail forwarding simply redirects messages from one address to another without any review process, lacking the oversight that moderation provides.