Using procmail to send cron output to local mailbox

A little background:

With Fedora 20, an MTA is no longer installed by default.  The 
assumption is, only servers really need an MTA, and if a client system 
needs one, the system owner is smart enough to figure out to install one.

Well I use cron for various tasks on my notebook, and I am trying to get 
local delivery to work without an MTA.  After days of going back and 
forth on the Fedora user list, it has come down to procmail able to 
deliver mail locally without an MTA.  So in /etc/sysconfig/crond I have:

# Settings for the CRON daemon.
# CRONDARGS= :  any extra command-line startup arguments for crond
CRONDARGS=-m "/usr/bin/procmail"

and this works in terms of getting content into /var/spool/mail/rgm, but 
the content is not a valid mailbox for mutt to process it.  Here is the 
content of my mailbox.  Note no starting or ending blank line(s):

From: "(Cron Daemon)" <rgm>
To: rgm
Subject: Cron <rgm@lx120e> rsync -tvz ftp.rfc-editor.org::rfcs/*.txt 
/home/common/ietf/rfcs
Content-Type: text/plain; charset=UTF-8
Auto-Submitted: auto-generated
Precedence: bulk
X-Cron-Env: <XDG_SESSION_ID=45>
X-Cron-Env: <XDG_RUNTIME_DIR=/run/user/1000>
X-Cron-Env: <LANG=en_US.utf8>
X-Cron-Env: <SHELL=/bin/bash>
X-Cron-Env: <PATH=/sbin:/bin:/usr/sbin:/usr/bin>
X-Cron-Env: <MAILTO=rgm>
X-Cron-Env: <HOME=/home/rgm>
X-Cron-Env: <LOGNAME=rgm>
X-Cron-Env: <USER=rgm>

skipping non-regular file "rfc-ref.txt"
RFCs_for_errata.txt
rfcxx00.txt

sent 3,486 bytes  received 125,267 bytes  15,147.41 bytes/sec
total size is 365,871,233  speedup is 2,841.65

=========================================

Is there a procmail receipt that will create a proper mailbox?  I want 
to see if I can do this before throwing in the towel and installing 
postfix...