specify SMTP relay server in mutt

[Sunhux G]

Removed  "-a /tmp/tst.tar.gz" & still get the same error.

Figured that /root/dead.letter is actually a logfile & its
contents is shown below:

# more /root/dead.letter

Date: Fri, 18 Jul 2014 19:01:58 +0800
From: root at current_svr.mgmt.a-cloud.gov.au
To: sunhux at gmail.com
Subject: rh1 via smtp1
Message-ID: <53c8fea6.0u+3/R+bETa4Hsbt%root at current_svr.mgmt.a-cloud.gov.au>
User-Agent: Heirloom mailx 12.4 7/29/08
MIME-Version: 1.0
Content-Type: multipart/mixed;
 boundary="=_53c8fea6.QPYvMxRlHrS05uxwNfXaW0elMaSu2c32+VTgj87G8Ruar7Yz"
This is a multi-part message in MIME format.
--=_53c8fea6.QPYvMxRlHrS05uxwNfXaW0elMaSu2c32+VTgj87G8Ruar7Yz
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
root:x:0:
bin:x:1:bin,daemon
. . .