The mailhub seems to be a good place to think about. Leave a "tail -f /var/log/mail/current" running in a shell while you wait for a cron to be executed. When it runs, check out what happens in the logfile.
Regards, Saffi -- Ricardo Saffi Marques Laboratório de Administração e Segurança de Sistemas (LAS/IC) Universidade Estadual de Campinas (UNICAMP) Cell: +55 (19) 8128-0435 Skype: ricardo_saffi_marques Website: http://www.rsaffi.com