Krishna,
I believe I have already informed you last year that the mailing list gets cleared at least once a week, and that has been largely happening since the list was founded by hpnadig. If you personally wish to volunteer as a moderator or know someone who wishes to do so, then please state so clearly. There is no point in passive-aggressively bringing this up once every year in case one of your friends is unable to do something they want to do. If I recall correctly, even last time you were suggesting that we ought to clear emails sent by non-members to the list.
>Recently a user approached me that they've been unable to subscribe to mailing list directly, and they got a message they require admin approval.
I have no idea why that should have happened. I have not received any email from such user expressing trouble joining the mailing list. As you should know by now, joining this mailing list does not require admin approval.
--Anirudh