/bin/sh: root: command not found
When we get this error cron is trying to execute a command with the name "root", which does not exist.
This is because cron expects a command in the sixth field.
If you are making changes in a local cron file using crontab -e, the job entry should contain 6 fields (not the username)
* * * * * /home/myfolder/myshell.sh
A wrong entry like this:
* * * * * root /home/myfolder/myshell.sh
would cause cron to interpret "root" as a command.
The syntax "* * * * * root /home/myfolder/myshell.sh" is valid for system crontab file /etc/crontab.
Then it migh happen that all this error messages filled up the mail queue.
To check how many pending mail you have
Launch this command:
cat /dev/null > /var/mail/root
And it will delete all mail from user root.
If you need a command line mail client to check up things you can use mutt.