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Attachments from outlook show as "winmail.dat"


We recently moved to a new server and updated from 2.7.0 to 2.7.2 in the process.
(from Ubuntu 9.04 to ubuntu 10.04 LTS)

Now, one member of our supportstaff has noticed that attachments from outlook apears as winmail.dat

I dont believe this was the case with our old installation. Am I missing something?


Perhaps it’s just a coincidence? HelpSpot hasn’t changed anything in attachment handling between those releases and all it does is log the attachments, it doesn’t transform them in anyway.


So HelpSpot can’t handle attachments from outlook?

It’s common for microsofts email tools (outlook etc) to send attachments as “application/ms-tnef” that will appear as winmail.dat in applications that don’t support tnef encodded attachment(s).

I know it’s not the “Internet standard” but Microsoft is really hard to ignore. Most of our customers are from the public sector and most use outlook as their one and only e-mail app.

I hope this feature will be added in a future release.


Unrelated to HelpSpot itself, perhaps this page would be useful:

There’s a setting in an exchange account that prevents messages being converted to winmail.dat
or something like that.


We’ll take a look at that Hans. I have to say we’ve never once had this request and certainly our customers customers send them email in Outlook all the time.

As John has posted I wonder if it’s actually a bug in your server configuration/network config as seems to be indicated by the link he posted.


We don’t use exchange. However, I suspect a lot of our customers do. (But that is out of our hands)
TNEF can also be turned off (at least partially) in outlook clients:

There’s also a short into to TNEF on wiki-pedia:

I’ve found this tool to open winmail.dat files as a workaround (there are other tools. use google):

PS. I just did a quick look in our helpspot db. There are 1,134 entries in HS_Documents. 206 of them are winmail.dat with mimetpye application/ms-tnef.

SELECT * FROM HS_Documents WHERE sFilename=‘winmail.dat’ AND sFileMimeType=‘application/ms-tnef’


We are also experiencing this issue.

"To resolve this issue, change the settings in Active Directory Users and Computers so that the mail-enabled contact does not use RTF as the default message format. "

Does any one know if this fixed the issue, before I ask our customers to change their Exchange server settings?


Yes, it’d be interesting to know if you’re both on exchange.

What would be very useful is if you could get a copy of the raw email (.eml) and email that in to us. We could then look at the raw message and see if this is something HelpSpot can adjust for or not. I think it’s unlikely only because HS is receiving the attachment as .dat when it receives it so it’s already in that format, but perhaps we’d be able to reverse it or determine the original in some way.


We are not using Exchange but the customer might be.

Does Helpspot download the eml file somewhere so we can forward it on to you?


No, it just parses the data. If you forward your email to a backup account you’d then have access to the raw email. So it might be worth doing that if you have an extra account to spare. It’s also possible your email provider has backups you can access.


The winmail.dat format is also known as ms-tnef. You can read more about on wikipedia.

I would also like to add that we don’t use exchange, but that some of our customers probably do.

This is not only a problem with exchange servers. Outlook will also send ms-tnef (in some cases even when RTF is disabled)