I recently migrated webservers and have run into problems with a PHP
application that sends HTML emails to a mailing list. Outlook seems to
have no trouble rendering the email, but they show up as blank
messages in the Mac OS X mail client.

The old server ran apache 1.3.26, php4 and SMTP locally via sendmail. 
The new server also runs apache 1.3.26 and php4 but SMTP is handled
externally by another server running exim.  The new webserver runs
exim localally as well. All three boxes run Debian Woody.

The only difference I see in email that the application sends on the
two machines send is in the ordering of the headers.  Here's what they
look like in email from old server (which sends the properly rendered
email):

Received: from webserver.xxxx.com (HOSTNAME [192.168.254.1]) by
localmail.xxxx.com with SMTP (Microsoft Exchange Internet Mail Service
Version 5.5.2658.3)
	id PD7FSSKK; Wed, 21 Jul 2004 13:02:55 -0700
Received: from webserver.xxxx.com (localhost [127.0.0.1])
	by webserver.xxxx.com (8.12.3+3.5Wbeta/8.12.3/Debian-6.4) with ESMTP
id i6LL8bFT019029
	for <to-addt@xxxx.com>; Wed, 21 Jul 2004 14:09:17 -0700
Received: (from www-data@localhost)
	by xxxx.xxxx.com (8.12.3+3.5Wbeta/8.12.3/Debian-6.4) id i6LL8bih019027;
	Wed, 21 Jul 2004 14:08:37 -0700
Date: Wed, 21 Jul 2004 14:08:37 -0700
Message-Id: <200407212108.i6LL8bih019027@webserver.xxxx.com>
To: to-addr@xxxx.com
Subject: blah blah blah
From: list@xxxx.com
MIME-Version: 1.0
Content-Type: multipart/mixed;
	boundary="PMP------aafcc4dd78b54ce4cc330fbb148ffb8b"
Content-Transfer-Encoding: 7bit

And here is a header from the broken server:

Received: from smtpserver.xxxx.com (reversedns.xxxx.net [external IP])
by localmail.xxxx.com with SMTP (Microsoft Exchange Internet Mail
Service Version 5.5.2658.3)
	id Z7B57LZY; Sun, 6 Feb 2005 06:52:25 -0800
Received: from [192.168.254.51] (helo=newweb.xxxx.com)
	by smtpserver.xxxx.com with esmtp (Exim 3.35 #1 (Debian))
	id 1CxoWS-0001xj-00
	for <toaddr.xxxx.com>; Sun, 06 Feb 2005 07:40:28 -0800
Received: from www-data by newweb.xxxx.com with local (Exim 3.35 #1 (Debian))
	id 1CxnhJ-0006qo-00
	for <toaddr.xxxx.com>; Sun, 06 Feb 2005 06:47:37 -0800
To: toaddr.xxxx.com
Subject: blah blah blah
From: list@xxxx.com
MIME-Version: 1.0
Content-Type: multipart/mixed;
	boundary="PM[------8711e218aea19e1573e7c096d3bdfaa8"
Content-Transfer-Encoding: 7bit
Message-Id: <E1CxnhJ-0006qo-00@newweb.xxxx.com>
Sender: www-data <www-data@newweb.xxxx.com>
Date: Sun, 06 Feb 2005 06:47:37 -0800



The PHP application has not changed at all between the servers.

Thanks a ton,

dean.