However, a huge number of messages end up in moderation ("Message Approval Needed") for no reason we can discern.

• the posting member's Posting Privileges is set to Override: moderated;
• the posting member's Posting Privileges is set to Override: new user moderated and their approval count is non-zero;
• the posting member's Posting Privileges is set to Use Group Moderation Setting and the Moderated box is checked in the Spam Control section of the group's Settings page;
• the Allow Non Subscribers to Post box is checked in the Message Policies section of the groups Settings page and the posting email address is not currently in the group's Members list;
• the message Subject contains a hashtag with the Moderated box checked;
• the Automatically Moderate Topics Older Than x days box is checked in the Message Policies section of the group's Settings page and the message is a reply to an older topic;
• the message is a reply to a topic that a moderator  has manually set to Moderate Topic;
• the Viruses option is set to Moderated in the Message Policies section of the group's Settings page and the message contains suspected malware; or
• the Attachments option is set to Moderate in the Message Formatting section of the group's Settings page and the message contains one or more attachments.