The notification “You have a new mail in /var/spool/mail/root” may occasionally appear in your EC2/Linux system after you execute a command.
OR you could be greeted by the message You have new mail in /var/mail/root when logging into your Ubuntu/Linux server.
Typically, they are system-generated messages that include cron job output, a log-watch system security report, or other messages. It is always good practice to read it.
Simply enter the below command to read them out.
cat /var/spool/mail/ec2-user
The messages will all be loaded by this command. Depending on the volume of mails, it can take some time.