Replying to a reply of a reply in hotmail is generating corrupted email headers because Hotmail is inserting a X-OriginalArrivalTime header in the middle of the References header block.
I've included below a full packet sniff of the transaction to show that the problem is on the hotmail side.
###
T 65.55.116.49:23588 -> 67.228.21.224:25 [A]
......
###
T 67.228.21.224:25 -> 65.55.116.49:23588 [AP]
220 mx1.ctgameinfo.com ESMTP Postfix.
#
T 65.55.116.49:23588 -> 67.228.21.224:25 [AP]
EHLO blu0-omc1-s38.blu0.hotmail.com.
#
T 67.228.21.224:25 -> 65.55.116.49:23588 [AP]
250-mx1.ctgameinfo.com.
250-PIPELINING.
250-SIZE 10240000.
250-VRFY.
250-ETRN.
250-AUTH LOGIN PLAIN.
250-AUTH=LOGIN PLAIN.
250-ENHANCEDSTATUSCODES.
250-8BITMIME.
250 DSN.
#
T 65.55.116.49:23588 -> 67.228.21.224:25 [AP]
MAIL FROM:<{removed email address}> SIZE=3587.
#
T 67.228.21.224:25 -> 65.55.116.49:23588 [AP]
250 2.1.0 Ok.
#
T 65.55.116.49:23588 -> 67.228.21.224:25 [AP]
RCPT TO:<{removed email address}>.
#
T 83.18.80.98:56248 -> 67.228.21.224:25 [A]
......
#
T 67.228.21.224:25 -> 83.18.80.98:56248 [AP]
220 mx1.ctgameinfo.com ESMTP Postfix.
####
T 83.18.80.98:56248 -> 67.228.21.224:25 [AP]
EHLO axc98.internetdsl.tpnet.pl.
#
T 67.228.21.224:25 -> 83.18.80.98:56248 [AP]
250-mx1.ctgameinfo.com.
250-PIPELINING.
250-SIZE 10240000.
250-VRFY.
250-ETRN.
250-AUTH LOGIN PLAIN.
250-AUTH=LOGIN PLAIN.
250-ENHANCEDSTATUSCODES.
250-8BITMIME.
250 DSN.
#
T 83.18.80.98:2913 -> 67.228.21.224:25 [A]
......
#
T 67.228.21.224:25 -> 83.18.80.98:2913 [AP]
220 mx1.ctgameinfo.com ESMTP Postfix.
#
T 67.228.21.224:25 -> 65.55.116.49:23588 [AP]
250 2.1.5 Ok.
#
T 65.55.116.49:23588 -> 67.228.21.224:25 [AP]
DATA.
#
T 67.228.21.224:25 -> 65.55.116.49:23588 [AP]
354 End data with <CR><LF>.<CR><LF>.
#
T 65.55.116.49:23588 -> 67.228.21.224:25 [A]
Received: from BLU149-W41 ([65.55.116.8]) by blu0-omc1-s38.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959);.
. Thu, 1 Oct 2009 14:47:35 -0700.
Message-ID: <{removed email address}>.
Return-Path: {removed email address}.
Content-Type: multipart/alternative;.
.boundary="_1adbe0ca-ce21-4c29-a6e0-ea642d006ed0_".
X-Originating-IP: [69.31.174.220].
From: "cstdenis ." <{removed email address}>.
To: <{removed email address}>.
Subject: RE: test message.
Date: Thu, 1 Oct 2009 21:47:34 +0000.
Importance: Normal.
In-Reply-To: <{removed email address}>.
References: <{removed email address}>.
<{removed email address}>.
X-OriginalArrivalTime: 01 Oct 2009 21:47:35.0093 (UTC) FILETIME=[C94E2650:01CA42E0].
.
.
<{removed email address}>.
MIME-Version: 1.0.
.
--_1adbe0ca-ce21-4c29-a6e0-ea642d006ed0_.
Content-Type: text/plain; charset="iso-8859-1".
Content-Transfer-Encoding: quoted-printable.
.
.
Test.
.
----.
Cstdenis.
http://www.CTgameinfo.com.
http://FanartCentral.cjb.net.
.
.
.
Date: Thu=2C 24 Sep 2009 15:40:09 -0700.
From: {removed email address}.
To: {removed email address}.
Subject: RE: test message.
.
Another reply from Roundcube.
.
=20.
.
On Thu=2C 24 Sep 2009 22:39:16 +0000=2C "cstdenis ." <{removed email address}>=.
wrote:.
.
This is a test reply.
.
.
.
.
Date: Thu=2C 24 Sep 2009 15:38:38 -0700.
From: {removed email address}.
To: {removed email address}.
Subject: test mes
#
T 65.55.116.49:23588 -> 67.228.21.224:25 [A]
sage.
.
test message body.
.
.
--=20.
this si a test sig.
.
.
.
.
Insert movie times and more without leaving Hotmail=AE. See how..
=20.
.
.
--=20.
this si a test sig.
.. . .. =0A=.
_________________________________________________________________=0A=.
Insert movie times and more without leaving Hotmail=AE.=0A=.
http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=3DTXT_TAGLM_WL_HM_Tut=.
orial_QuickAdd_062009=.
.
--_1adbe0ca-ce21-4c29-a6e0-ea642d006ed0_.
Content-Type: text/html; charset="iso-8859-1".
Content-Transfer-Encoding: quoted-printable.
.
<html>.
<head>.
<style><!--.
..hmmessage P.
{.
margin:0px=3B.
padding:0px.
}.
body.hmmessage.
{.
font-size: 10pt=3B.
font-family:Verdana.
}.
--></style>.
</head>.
<body class=3D'hmmessage'>.
Test<br><br>----.
Cstdenis.
http://www.CTgameinfo.com.
http://FanartCentral.cjb.net<br><br><br><br><hr id=3D"stopSpelling">Date: T=.
hu=2C 24 Sep 2009 15:40:09 -0700<br>From: {removed email address}<br>To: cstdenis@=.
hotmail.com<br>Subject: RE: test message<br><br>Another reply from Roundcub=.
e<BR>.
 =3B<BR>.
On Thu=2C 24 Sep 2009 22:39:16 +0000=2C "cstdenis ." <={removed email address}=.
..com>=3B wrote:<BR>.
<blockquote style=3D"border-left: 2px solid rgb(16=2C 16=2C 255)=3B padding=.
-left: 5px=3B margin-left: 5px=3B width: 100%=3B"> This is a test reply<br>=.
<br><br>.
<hr id=3D"ecxstopSpelling">.
Date: Thu=2C 24 Sep 2009 15:38:38 -0700<br>From: {removed email address}<br>To: cs=.
{removed email address}<br>Subj
#
T 65.55.116.49:23588 -> 67.228.21.224:25 [AP]
ect: test message<br><br>test message body<br>.
<div>.
<pre>-- <br>this si a test sig</pre>.
</div>.
<br>.
<hr>.
Insert movie times and more without leaving Hotmail=AE. <a href=3D"http://w=.
indowslive.com/Tutorial/Hotmail/QuickAdd?ocid=3DTXT_TAGLM_WL_HM_Tutorial_Qu=.
ickAdd_062009">See how.</a></blockquote>.
 =3B<BR>.
<div>.
<pre>-- <br>this si a test sig</pre>.
</div> .. . .. <br /><hr />Insert movie times and more without leaving H=.
otmail=AE. <a href=3D'http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=.
=3DTXT_TAGLM_WL_HM_Tutorial_QuickAdd_062009' target=3D'_new'>See how.</a></=.
body>.
</html>=.
.
--_1adbe0ca-ce21-4c29-a6e0-ea642d006ed0_--.
..