The "winmail.dat" file is actually unique to MS Outlook/Exchange
clients, and Outlook/Exchange clients are the only e-mail clients that
are supposed to be able to automatically interpret them. Therefore, if
you are seeing a "winmail.dat" file attachment in an e-mail that you
have received in Outlook, then chances are that the actual
"winmail.dat" file is corrupt; there are no settings required as
Outlook automatically handles this file as long as it is not corrupt.
If you are wanting to experiment with this, then I recommend that you
first read this page:
Dealing with the winmail.dat file
and then, download the decoding program mentioned on the page, available from:
(the file to get is the free version of WMDecode)
Now, before I end this Answer to give you a chance to try the above,
please note that if you are using MS Outlook Express instead of
Outlook as your mail client, then you may indeed see the "winmail.dat"
attachment appearing due to the sender using rich-text formatting. In
which case, I refer you to the extra information on the biblet
webpage, in the WMDecode section, that refers to using Notepad to save
the raw e-mail data, then WinZip to decode the contents into a
winmail.dat file, then WMDecode to extract any usable attachments.
Please let me know if any of the above works for you; if not, please
provide me additional information such as the version of Outlook that
you are using, the e-mail client that the sender is using to create
the e-mails that you are receiving, and any software such as anti-spam
programs that you may have installed on your PC that could potentially
be changing incoming e-mails on you.
Google Answers Researcher
Clarification of Answer by
07 Jul 2004 07:27 PDT
OK, that's a different situation than I interpreted from your original question. :)
There's a few additional questions that I need you to answer:
1. You are using MS Outlook 2002/XP SP3 (you said 2003, but there are
no service packs yet for Outlook SP3), are you using it with an
Exchange server or are you instead using it in "Internet Mail Only"
2. The recipients, are they using the same physical e-mail server that
you are, or are they receiving the e-mail through "the Internet"?
3. Are you sending the task update requests using address book
entries, or straight to an SMTP address entered directly into the
'To:' field, along the lines of: email@example.com ?
The reason for these questions is because of the information included
in the following links:
How to Prevent the Winmail.dat File from Being Sent to Internet Users
(IMO) Winmail.dat Attachments Included in Received Messages
Essentially, the winmail.dat file is generated by the Outlook client
whenever an e-mail composed in Rich Text Format (RTF) is sent. The
winmail.dat file encapsulates the RTF formatting as well as the
contents of the e-mail including attachments. This winmail.dat file
can only be viewed properly if transmitted unaltered to a recipient
using MS Outlook. "Unaltered" means that none of the e-mail servers
that may be between you and the recipients are reformatting the
contents of the e-mail (through anti-spam or anti-virus efforts for
So, can you describe your e-mail "connections" in greater detail for
me, and also describe how you are sending the task update requests?
Google Answers Researcher