It looks like you set this up for the root user. You should be able to put the MAILTO="" at the top or root's cron jobs to prevent it from sending you mail.
Was that line added by a postgresql installation of some kind? It's going to error a lot, because the task.queue file is designed to not exist most of the time.
If you require this line, then change it to look like this:
Jeff, isn't that "fix" going to cause any nasty race conditions? Where the PGsql task file gets truncated before it's actually been taken care of ? Or will the output not get redirected if cat doesn't return 0 ?