One thing to remember is that the MAILTO variable will be used in all subsequent cron jobs
Code:
MAILTO=""
0 0 * * * command1 && command2 && command3 && command4 && command5
1 1 * * * command1 && command2 && command3
MAILTO=root
2 2 * * * command1 && command2
In this example the first two jobs will not produce any emails. In order to get an email for the third job, you will have to set MAILTO again.
To prevent this I find it easier is to move all the no-email-wanted jobs to the end:
Code:
MAILTO=root
2 2 * * * command1 && command2
MAILTO=""
0 0 * * * command1 && command2 && command3 && command4 && command5
1 1 * * * command1 && command2 && command3