user@linux5:~$ echo test | mail user
user@linux5:~$ mail
Mail version 8.1.2 01/15/2001.  Type ? for help.
"/var/mail/user": 2 messages 2 new
>N  1 user@linux5.unix.  Mon Jun 20 14:28   18/731   *** SECURITY information for linux5.unix.nt ***
 N  2 user@ny.unix.nt    Tue Jun 21 14:17   15/553
& t1
Message 1:
From user@linux5.unix.nt Mon Jun 20 14:28:02 2011
Envelope-to: root@linux5.unix.nt
Delivery-date: Mon, 20 Jun 2011 14:28:02 +0300
Date: Mon, 20 Jun 2011 14:28:02 +0300
To: root@linux5.unix.nt
Auto-Submitted: auto-generated
Subject: *** SECURITY information for linux5.unix.nt ***
From: user <user@linux5.unix.nt>
linux5.unix.nt : M-PM^XM-QM^NM-PM-= 20 14:28:02 : user : user NOT in sudoers ; TTY=pts/0 ; PWD=/home/user ; USER=root ; COMMAND=/usr/bin/apt-get install dhcp3-server
& t2
Message 2:
From user@ny.unix.nt  Tue Jun 21 14:17:17 2011
Date: Tue, 21 Jun 2011 14:17:17 +0300
From: user <user@ny.unix.nt>
To: user@ny.unix.nt
test
& q
Saved 2 messages in /home/user/mbox
user@linux5:~$ echo test | mail user@la.unix.nt
user@linux5:~$ mail
No mail for user
user@linux5:~$ mail
No mail for user
user@linux5:~$ su
Пароль: