A friend of mine uses Outlook Express because that has been with Windows since very early on, and before that with Internet Explorer from version 4 till version 6.
He is the kind of person that does use a computer, but doesn’t like change. No wonder, as he is well into the retirement age and the systems he has used in the past all lasted for a very long time.
So it is going to be a big change for him when he needs to upgrade from Windows XP – that he used for over 10 years – to something else. Probably more on that in a later stage (if Windows Live Mail exists by then).
Back to the problem at hand: he couldn’t see attachments from certain Outlook users, though those users insisted .
I hadn’t used Outlook nor Outlook Express for a long while but it was fairly easy to track down the cause by viewing the message source in either of these two ways:
- From the opened message itself: view the message properties, then the message source as described in How to View and Forward Email Headers.
- From the message list: Press Ctrl-F3 to view the full message source (which also seems to work from the opened message itself).
As soon as you see the full message source, there is a ms-tnef encoded Winmail.dat attachment in the affected messages. You find it by searching for a line that starts with “begin” followed by 2 spaces, “666” or “664” (it is one of the means to fake UUencoded attachments and hide text from Outlook Express).
Winmail.dat is known to cause all sorts of problems, even the NY Times devoted an article about it. It basically encapsulates the content of a message including any attachments into RTF: a Microsoft proprietary – but documented – standard of encoding formatted text.
Outlook Express does not cope with Winmail.dat well: it is a typical example of the one hand doesn’t know what the other is doing.
The “trick” is to configure Outlook for using HTML to format text (or use plain text without formatting) instead of RTF. You can do this either globally, or per recipient in the address book:
- Recipients receive a winmail.dat attachment – Outlook – Office.com.
- Email received from a sender using Outlook includes a Winmail.dat attachment.
So when you use Outlook Express, ask the sender not to use RTF.
–jeroen