When logging into your Ubuntu server, you might be greeted with the message You have new mail in /var/mail/root. But how do you read that mail and how did it get there?

It means that you have installed sendmail on Ubuntu (or any other flavour of Linux) and you received one or more messages in your inbox. The message(s) can originate from your system itself, or from an external e-mail address.

Read your messages in Ubuntu

To see what messages you received from the command line, this command will reveal the message(s):

<code>cat /var/spool/mail/root</code>

The message could look like this:

From root@hostname Wed Jul 29 12:05:26 2015
Return-Path: <root@hostname>
Received: from hostname (localhost [127.0.0.1])
by hostname (8.14.4/8.14.4/Debian-4.1ubuntu1) with ESMTP id t6TG5QKu001540
for <root@hostname>; Wed, 29 Jul 2015 12:05:26 -0400
Received: (from root@localhost)
by hostname (8.14.4/8.14.4/Submit) id t6TG5QYK001533;
Wed, 29 Jul 2015 12:05:26 -0400
Date: Wed, 29 Jul 2015 12:05:26 -0400
Message-Id: <201507291605.t6TG5QYK001533@hostname>
To: root@hostname
From: root@hostname
Auto-Submitted: auto-generated
Subject: *** SECURITY information for hostname ***

hostname: Jul 29 12:05:26 : root : unable to resolve host hostname

Removing messages from /var/mail/root

To purge these messages and to get rid of the message you received on logging in, you can simply delete it with this command:

root@hostname:~# > /var/spool/mail/root

Do not forget to include the > sign, otherwise it won’t work.