Question about "mutt" vs "mail"

When I send an email from my linux box, within a script, for instance, -- If I use "mail" to send the email, it included my email in the "from" line.

Sending an email with "mutt" on the same box, does not.  (It just has my name and then "<>"
(see below)

when sent with mutt "from" line looks like this
From: Joe Username <>

when sent with mail "from" line looks like this
From: Joe Username <jusername@mydomain.com>

Can anyone tell me why this is, and how I can fix it.

FYI: my server is running RedHat ES3.  Let me know if you need any more details.

More details from headers......
When sent using "mutt" this is what shows below the date line in the headers

From: Joe Username <>
To: someone@gmail.com
Subject: test 11
Message-ID: <20080808224123.GA8838@TCTRSRVL2>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.4.1i


When sent using "mail" this is what shows below the date line in the headers

From: Joe Username <jusername@mydomain.com>
Message-Id: <200808082239.m78Md8NK008769@localhost.localdomain>
To: someone@gmail.com
Subject: test 10