The CSSMTP application processes the spool file that contains mail messages and forwards those mail messages to a target server where a mail recipient receives the mail. The following is an example of receiving mail:

Received: from VIC000.XYZdomain.com (VIC000)
by VIC000.XYZdomain.com (VIC000 [1.1.1.1])
for <USER1.VIC000> (USER1.VIC000)
with ESMTP (IBM CSSMTP z/OS V01R11.00)
Id <USER1C.JOB00035.VIC000@XYZdomain.com.Sep062008.101336.934866.1> ;
Sat, 06 Sep 2008 10:13:37 -0400
Date: Thur, 5 Sep 2008 10:12:57 -0400
From: Carol <CAROL@YOUR.MVSDOMAIN.COM>
To: someuser@some.domain.com
Cc: Alice <alice@ai.our.edu>
Subject: update
Message-ID: <USER1C.JOB00035.VIC000@XYZdomain.com.Sep062008.101336.934866.1>

Mike: Cindy stubbed her toe.  Bobby went to
      baseball camp.  Marsha made the cheerleading team.
      Jan got glasses.  Peter has an identity crisis.
      Greg made dates with 3 girls and couldn't
      remember their names.