I moderate a few yahoo groups and uic_incoming is the most active of them. Until recently, we had been having a big problem with a lot of people sending personal mails to the group. Mails that were meant for one person were being distributed to all the 650+ members.
We recently put the board into moderation, as in, all the mails would first be approved by the moderators and then be display on the group. But that put a lot of burden on us mods. So, I changed one setting. I went to Management (only mods see this) and then went to Messages under the Group Settings. Then I went on to edit he settings for Posting and Archiving and just set the reply-to option to *sender* and not *all members*.
This has greatly reduced the number of mails that have been coming in for moderation.