Turn off mail notification in terminal
Solution 1:
It's likely to be in the spool file: /var/mail/$user. Because sometimes your mailbox will contain important messages (a failed cronjob task, etc.) you don't to check it every time by yourself.
Also, you can check man mail
Solution 2:
I think if you add this line to your ~/.bashrc file, the notifications will go away.
unset MAILCHECK
Solution 3:
Mac OS X runs "login" each time a login occurs. So, no matter what the setting is for Bash, the "login" will tell you about mail whenever you login.
However, if you have a ~/.hushlogin
file, the login process will be quieter and (hopefully) not bother you.
Apple's man page for "login"