Overview
If you are the owner or moderator of a moderated list, you are responsible for approving or rejecting any pending messages or subscription requests. You will receive an email when a message is waiting for moderation. An example of those emails is below:

When such a message is received, any of the individuals set as list owners must either Approve or Reject. If you're uncertain whether or not a message should be approved, you can leave the approval request message without deleting it and without clicking Approve or Reject until you're sure.