OpenOffice ODT files spamtrapped?

[#1]

This is driving me nuts!
I've tried to send a .ODT file four times to another PlusNet recipient.  Only when I converted the document to a .DOC format on the fifth attempt would it be received.  It's not even appeared in their spam folder, it has literally disappeared off the face of the earth.
Anyone any ideas?

[#2]

Could it be the file size?
I recently converted an odt to pdf to send by email for this reason.

[#3]

Thanks Whiffler
Looking at your attachment that is a huge increase in size!
However in my case it is 21kb for the ODT, 15kb for the DOC.
I was wondering whether it is the file name, Tribute in my case, could it be on a black list?

[#4]

I have two independent Plusnet accounts, and I just sent an email with a 19.3KB .ODT word processor file attached from one account to the other, and it worked perfectly 

[#5]

Thanks for testing purleigh
The emails have arrived now, much much later (a couple of hours) than expected.  Long after after the .DOC which was sent later had arrived.
I was emailing these files from one of my email addresses to another on the same account used by another family member. It's like the .ODT took a different route.  Almost like they were examined manually for spam?
Curiouser and curiouser.

[#6]

Looking through the email header of my test message with ODT attachment, it took FOUR seconds from when I sent it, to the time it arrived in my other mailbox !

[#7]

Can you post the headers (with email addresses munged) please.

[#8]

This one with the .ODT attachment took 24 hours to arrive:
Return-path: <*******@**.plus.com>
Envelope-to: *****@**.plus.com
Delivery-date: Thu, 01 Jul 2010 13:56:43 +0100
Received: from [212.159.7.34] (helo=mx.ptn-ipin02.plus.net)
  by pih-inmx13.plus.net with esmtp (PlusNet MXCore v2.00) id 1OUJJr-0004hy-CX
  for *****@**.plus.com; Thu, 01 Jul 2010 13:56:43 +0100
Received-SPF: None identity=pra; client-ip=84.92.1.97;
  receiver=mx.ptn-ipin02.plus.net;
  envelope-from="*******@**.plus.com";
  x-sender="*******@**.plus.com";
  x-conformance=sidf_compatible
Received-SPF: None identity=mailfrom; client-ip=84.92.1.97;
  receiver=mx.ptn-ipin02.plus.net;
  envelope-from="*******@**.plus.com";
  x-sender="*******@**.plus.com";
  x-conformance=sidf_compatible
Received-SPF: None identity=helo; client-ip=84.92.1.97;
  receiver=mx.ptn-ipin02.plus.net;
  envelope-from="*******@**.plus.com";
  x-sender="postmaster@relay.ptn-ipout02.plus.net";
  x-conformance=sidf_compatible
X-SBRS: 5.3
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AoYFmWLLKkxUXAFhmWdsb2JhbACBHodYhmEDg0iBFoM9h3gBAQIBCAsKBxEiQr50DYIKBIMKBA
X-IronPort-AV: E=McAfee;i="5100,188,6028"; a="22128217"
X-IronPort-AV: E=Sophos;i="4.53,511,1272841200";
  d="xml'?rdf'?odt'72,48?png'72,48,150?scan'72,48,150,208,217,48,150,72";a="22128217"
X-IronPort-AV: E=McAfee;i="5100,188,6029"; a="22128217"
X-IronPort-AV: E=Sophos;i="4.53,518,1272841200";
  d="xml'?rdf'?odt'72,48?png'72,48,150?scan'72,48,150,208,217,48,150,72";a="22128217"
Received: from mx.ironport.plus.net (HELO relay.ptn-ipout02.plus.net) ([84.92.1.97])
  by mx.ptn-ipin02.plus.net with ESMTP; 30 Jun 2010 13:52:55 +0100
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AkoOAM7aKkzUnw4S/2dsb2JhbACBH4dYhmMDg0iBFoM9iFS/aQ2FGAQ
Received: from outmx04.plus.net (HELO outmx06.plus.net) ([212.159.14.18])
  by relay.ptn-ipout02.plus.net with ESMTP; 30 Jun 2010 13:52:55 +0100
Received: from xx.plus.com ([80.229.217.nnn] helo=len)
by outmx06.plus.net with smtp (Exim) id 1OTwmc-00065G-D8
for xxxxx@xx.plus.com; Wed, 30 Jun 2010 13:52:55 +0100
Message-ID: <ECAC6FECEAAD4D81AD62A7335EAD5880@len>
From: "X X" <*******@**.plus.com>
To: <xxxxx@xx.plus.com>
Date: Wed, 30 Jun 2010 13:52:35 +0100
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_001D_01CB185B.7EC9B530"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2900.5931
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5931
X-PN-Virus-Filtered: by PlusNet MXCore (v5.00)
X-PN-Spam-Filtered: by PlusNet MXCore (v5.00)
Subject: Tribute
This had the .DOC attachment and arrived more or less straight away:
Return-path: <xxxxxxx@xx.plus.com>
Envelope-to: xxxxx@xx.plus.com
Delivery-date: Wed, 30 Jun 2010 14:11:19 +0100
Received: from [212.159.7.33] (helo=mx.ptn-ipin01.plus.net)
  by pih-inmx05.plus.net with esmtp (PlusNet MXCore v2.00) id 1OTx4Q-0003PD-EH
  for xxxxx@xx.plus.com; Wed, 30 Jun 2010 14:11:18 +0100
Received-SPF: None identity=pra; client-ip=84.92.1.97;
  receiver=mx.ptn-ipin01.plus.net;
  envelope-from="xxxxxx@xx.plus.com";
  x-sender="xxxxxxx@xx.plus.com";
  x-conformance=sidf_compatible
Received-SPF: None identity=mailfrom; client-ip=84.92.1.97;
  receiver=mx.ptn-ipin01.plus.net;
  envelope-from="xxxxxxx@xx.plus.com";
  x-sender="xxxxxxx@xx.plus.com";
  x-conformance=sidf_compatible
Received-SPF: None identity=helo; client-ip=84.92.1.97;
  receiver=mx.ptn-ipin01.plus.net;
  envelope-from="xxxxxxx@xx.plus.com";
  x-sender="postmaster@relay.ptn-ipout01.plus.net";
  x-conformance=sidf_compatible
X-SBRS: 5.3
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AoYFAMreKkxUXAFhmWdsb2JhbACBH4dYhmMDg0iBFoM9h3gBAQIBCAsKBxEiv38NhRgE
X-IronPort-AV: E=McAfee;i="5300,2777,6028"; a="325105919"
X-IronPort-AV: E=Sophos;i="4.53,513,1272841200";
  d="doc'32?scan'32,208,217,32";a="325105919"
Received: from mx.ironport.plus.net (HELO relay.ptn-ipout01.plus.net) ([84.92.1.97])
  by mx.ptn-ipin01.plus.net with ESMTP; 30 Jun 2010 14:11:13 +0100
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AkoOAEPfKkzUnw4S/2dsb2JhbACBH4dYhmMDg0iBFoM9iFTAAA2FGAQ
Received: from outmx04.plus.net (HELO outmx06.plus.net) ([212.159.14.18])
  by relay.ptn-ipout01.plus.net with ESMTP; 30 Jun 2010 14:11:13 +0100
Received: from xx.plus.com ([80.229.217.nnn] helo=len)
by outmx06.plus.net with smtp (Exim) id 1OTx4K-0004Un-4H
for xxxxx@xx.plus.com; Wed, 30 Jun 2010 14:11:12 +0100
Message-ID: <FF1B98A0B70A40CF9530BBA2A8E03356@len>
From: "X X" <xxxxxxx@xx.plus.com>
To: <xxxxx@xx.plus.com>
Date: Wed, 30 Jun 2010 14:10:54 +0100
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_0001_01CB185E.0DA5C030"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2900.5931
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5931
X-PN-Virus-Filtered: by PlusNet MXCore (v5.00)
X-PN-Spam-Filtered: by PlusNet MXCore (v5.00)
Subject: Xxxxx's tribute

[#9]

The first one seems to have gone through the virus/trojan checks twice.

Quote

X-IronPort-AV: E=McAfee;i="5100,188,6028"; a="22128217" X-IronPort-AV: E=Sophos;i="4.53,511,1272841200";   d="xml'?rdf'?odt'72,48?png'72,48,150?scan'72,48,150,208,217,48,150,72";a="22128217" X-IronPort-AV: E=McAfee;i="5100,188,6029"; a="22128217" X-IronPort-AV: E=Sophos;i="4.53,518,1272841200";   d="xml'?rdf'?odt'72,48?png'72,48,150?scan'72,48,150,208,217,48,150,72";a="22128217"

This might support the theory that the attachment was given special treatment?  But no idea why it would take so long....
Chris

[#10]

The emails are still arriving in dribs and drabs more than 24 hours later. There now seems to be more emails than I remember sending!?
It will be interesting to see what has happened to them.  The worst thing was they were really urgent at the time.