I am having strange problems with sendmail. I am not using my machine as public mail server, but would like to process local cron and other mail.

I'm using FC4 (2.6.12-1.1390_FC4) with sendmail (8.13.4-2) and none of cron-job reports get in to root's mail.
The mail just stucks in the clientmqueue directory and fills up disk space.

Is it a permission problem? I've read something about DontBlameSendmail, but don't know, weather it's a problem.
Or is it a configuration/update problem? Cron reports were working fine under FC3 and I was not changing the configuration files myself (only the update FC3->FC4?).