We found in our environment a while ago we were getting, no lots, but a few failed indexes on users EV mailboxes. To be pro-active about this I wrote this script which when run notifies admins by email the details of the failed user indexes. It also emails once a week (Mondays) just so you know the script is still running.
I have this scheduled twice a day every weekday which seems to be enough.
Again you will need to setup your database server, email details for this script to work, oh and rename the file to.vbs.