Andrea asked the question in another thread:

I would like to ask how long moderation lasts for a new user. It is now more than a week (with 7 posts) that Tarantas has been registered...

It looks like it lasts forever until I uncheck the "Mod" box in the mailing list for that user. I think this started only when additional security was added in the last year or so and I did not realize it and had just been approving the messages. Today I looked into it and from now on when I see a new addition, I will know to uncheck the "Mod" box right away.