Dave, there are a couple of people who send me email, and, consistently, their attachments don’t show up as neat “foo.doc” or “report.xls” but as the generic attachment winmail.dat. They don’t know why and I don’t know why. Worse, as a Mac user, I can’t figure out what to do with them. What’s causing these “winmail.dat” files and how do I decode ’em?
I too have variously been plagued with this winmail.dat affliction, and as far as I can tell, the problem is that Microsoft Exchange servers use the mysterious winmail.dat method of encoding attachments that are sent from one Microsoft Outlook user to another through a Microsoft Exchange server.
Of course, you clearly aren’t using Microsoft Outlook for Windows (since it would have magically decoded the attachment, leaving you none the wiser), and are instead faced with trying to decode this mysterious attachment…
Again, from what I’ve read, the real fix is for the sender to make a few tweaks to their Microsoft Outlook to ensure that their copy of Microsoft Exchange doesn’t think it’s sending to another Outlook user. It’s easy: they just have to indicate in their address book entry for you that you cannot receive Rich Text Format (RTF) rather than the current setting which assumes that you can and therefore must be running Outlook! Getting your colleagues to change their address books so that you have an easier time with their attachments might be, um, a bit tricky, however. 🙂
To simply unpack the attachments on your Mac, pop over to VersionTracker and search for “winmail.dat”. Surprise! You’ll find a link to a great little freeware app called TNEF’s Enough from Josh Jacob. Download and install it and you’ll be able to drag and drop these annoying winmail.dat files onto the app and have them unpack without incident.
That should solve your problem, or at least help you keep a tenuous grip on your sanity! Good luck.
Hi,
I am mac user. i am facing the problem with outlook 2011 mail . i am not receiving .PDF file.
i have received winmail.dat format. please provide the solution.
Thanks.
Brijesh
I only have issues with .dat files (photos) when sending from my computer outlook to my iphone. I solved this problem just not by adding myself to my address book and sending myself files in rich text format. THIS WORKED!!!!!! Thanks for this info.
Dave,
How about this: when I send Outlook emails with attachments to my Mac mail account I receive win.dat files – but the same email and attachments sent to my wife’s Mac mail account (same machine) arrive with the attachments intact. We even tried creating a new account for me but same thing – win.dat!. Wassup there??
I see that there are solutions to the winmail.dat problem for the MAC and PC users. I don’t understand why there isn’t a converter app (primarily for what should be PDF files) for the IPad 2. Are the developers trying to punish outlook developers and users?
Hi Dave
I have the same problem on my iPhone, but get
The emails fine on my pc(outlook)
Do you know offhand if changing from a pop3 to an exchange server will this stop the winmail.dat problem on my iPhone?
Thank you in advance for your advice
Frank.
Everyday I send my boss a report (as a PDF) from Quickbooks c/o Outlook. For the past 3 days he is having trouble opening them on his iPhone, they come up as winmail.dat. I dont want to have to change my mail format settings everytime I need to send him a PDF or other MS files, any suggestions. I found an app for him to download in the App Store for his iPhone “Winmail File Viewer” any other suggestions. Any suggestions as to why this is all of a sudden happening.
The best way is ti open it in MS OFFICE Word , then remove the ununderstandable texts or garbage manually and finally you will get the original message. I have corrected many mails like these.
I’m a windows user, with microsoft outlook 2007. Only recently I’ve noticed that I can’t send any attachments withouth them being sent as .dat files.
I’ve tried altering the way outlook sends messages at multiple different levels to ensure it sends as plain text (at account settings level, at individual mail recipient email address level) but these attachments still won’t send as anything other than .dat!!!
HELP PLEASE!!!
WARNING! I tried downloading from http://www.download.com/AkeeSoft-WMViewer/3000-2369_4-10383013.html?tag=lst-0-3 When I ran the file for installation, there was a msg stating that this is an older version and for the newer version I should connect to the main akeesoft website. There was a webface free program. Seemed interesting but when I tried downloading it ESET commented that it detected a potential threat. FYI.
Dave, I am a windows user, plus an outlook express user. I get these winmail.dat files from only one person. On the other hand my partner who also has the same programs gets the same files sent to both of us. I checked with my domain host they cant explain it. More trivial, I get the same attachment on the same outlook express if it sent to my other mail address hosted on another ISP. Another one of those windozs hick ups. In a perfect world I would rather get the problem fixed than just bypassing it with another software. Thanks anyway.
Thanks, I’m sending an inquiry to Josh Jacob.
Marge, pretty sure that you should be able to drag and drop the winmail.dat file onto the TNEF’s Enough icon and have it unpack, but note that it doesn’t work 100% of the time.
Here’s the developer’s site if you want to ask him directly: http://www.joshjacob.com/mac-development/tnef.php
Okay, I downloaded TNEF’s Enough for my imac running 10.5.8, but–DUH–I can’t see how to install it. I’ve tried dropping it into the applications folder, or dropping it into the applications/utilities folder. (The TNEF’s HELP screen didn’t seem to have instructions, and now even that won’t open–the general Mac help window comes up instead.) When I try to open a winmail.dat file, it opens VLC. If I tell it to open with TNEF’s Enough, it doesn’t open anything. Feeling really dumb here…would appreciate help. Thanks.
Dave, thanks for the info! The winmail.dat solution works very well, except for a couple of cases where it came up blank.
I am constantly defending my rights as a mac owner in this world of pc’s. I’ve been getting those dumb winmail.dat files more and more frequently and they were driving me nuts – id have to keep asking people to resend their attachments and they of course said “stupid macs can’t do anything – get a pc”. Loving TNEF and really glad to hear it’s not just macs that can’t open them…..
dave thanks so much for the help but i too found this info on microsoft and other sights and it hasn’t helped. I am the offending outlook sender and even when switching to plain text my recipients still get the dat files if i attach a .doc or .pdf for example. Any ideas?
tnefDD (http://tnefdd.sourceforge.net/) will decode winmail.dat files on Leopard. And is free.
Is there another version for 10.5?
Dave, you’ve come through again for me. The internet is a better place thanks to you.
When ever my dad or I get an e-mail with a .dat file attached to it, we can’t read or open the .dat file to view its contents. Any sugestions on where we can find a viewer to view these files with after we download them?
I tried downloading both OMiC, and TNEF’s Enough but I can’t get either of them to work in Mac Leopard (10.5). Any Suggestions?
Here is a free program that opens the winmail.dat file for Windows.
http://tinyurl.com/2w4cn7 Winmail Opener
Thanks for this, in 60 seconds I was back in business. Elegent little program. Now if they only had one for the folks in my office on PC’s that seem to get DAT files from me.
what about att####.DAT files.
I have trouble sending email with attachments to outlook users (sometimes). I do not use Outlook. Sometimes they receive the attachments fine, others they get changed to a .DAT file
Sometimes an online converter is the fastest way to open those attachments, for example http://www.winmaildat.com.
Thomas
It still works – this time on OS 10.4.9
made me very happy; though I had to go into TNEF’s Enough and find and open the saved attachment from there. Maybe it’ll be more automatic (i.e. open on double-clicking the attachement in Entourage) later… still ahppey a sis.
Many thanks to the developer and earlier commentators.
Paul
I’m using Mac OS X 10.2.8. The TNEF works for some files but not others. When I tried to open one winmail.dat using TNEF’s Enough Carbon (version 1.0), it said Error! And I tried downloading the version 2.0 of TNEF, but I couldn’t get the application to open. Finally, the OMiC software doesn’t seem to be supported by the computer. What seems to be the problem? Is it the file, which is in pdf format?? Thanks
Thanks Dave, the TNEF solution works perfectly. I appreciate your help!
Joel
You can also use filejuicer to extract those pesky windoze files:
http://echoone.com/filejuicer/
Hi Dave ,
i have my own painting company, one of my clients sends me plans with winmail.dat.
My computer programs don’t open them the computer is a toshiba harman/kardon.can you please advise me on a program that i can download or buy.
thank you very much Peter.
TNEF’s Enough works just as advertised, thanks, except that my Mac has a nag-ware copy of GraphicConverter hard-wired to load “winmail.dat” files. The “Open with …” trick works to switch single files to TNEF’s Enough, but if I try to “Change All..”, it magically reverts to GraphicConverter. Which can’t handle the file. And which, since I have no need for it and haven’t bought and registered it, insists on posting a modal splash screen with an ever-lengthening nag-ware timer to encourage me to pay for this thing I don’t want anyway but that insists on reinstalling itself even when I try not to run it.
Can you tell me how to un-wire GraphicConverter? It’s actually a fine tool (I’ve used it in the past, but no longer have the need). But this trick of forcing itself upon me just so it can nag at me is geting extremely annoying!
And thanks for having this site-
it’s an excellent public service!
I’ve had this problem, too. In reply to Gerry Lavender at August 30, 2005; here’s what I’m trying today:
(I use Windows ME) In my Outlook (2000) address book, right-click on the addressee’s name and select “Properties.” Go to the “Name” tab and then check the box “Send Email using plain text only” in the lower left corner.
I’ll let you know…
I have the reverse of the winmail dat problem, and am still working the problem. You may find this interesting or better yet have a solution. I have a mac with office for mac. I am sending an excel template which was drop/drag to my mac excel program. I send the file and it ends up as winmail dat at all windows recipients. I would like to be able to fix the problem on my side (mac side). Driving me a little crazy at this point.
I have the reverse of the winmail dat problem, and am still working the problem. You may find this interesting or better yet have a solution. I have a mac with office for mac. I am sending an excel template which was drop/drag to my mac excel program. I send the file and it ends up as winmail dat at all windows recipients. I would like to be able to fix the problem on my side (mac side). Driving me a little crazy at this point.
I have the reverse of the winmail dat problem, and am still working the problem. You may find this interesting or better yet have a solution. I have a mac with office for mac. I am sending an excel template which was drop/drag to my mac excel program. I send the file and it ends up as winmail dat at all windows recipients. I would like to be able to fix the problem on my side (mac side). Driving me a little crazy at this point.
I have the reverse of the winmail dat problem, and am still working the problem. You may find this interesting or better yet have a solution. I have a mac with office for mac. I am sending an excel template which was drop/drag to my mac excel program. I send the file and it ends up as winmail dat at all windows recipients. I would like to be able to fix the problem on my side (mac side). Driving me a little crazy at this point.
Yep, its only 12 kb, not much of a file! Thanks for your help.
Alfred, that’s entirely possible, actually. Check the file size, and ask the person who sent it if there was an attachment included?
Thanks Dave, I got it to open TNEF by clicking on the icon, but I still get no files to appear in the Embedded Files window. Might this drat file (I mean dat file) just not have any embedded files?
Alfred, right click (oops, sorry, Cmd-Click) on the .dat file and it should show you “Open With…” and you can pick the TNEF application. To permanently change this, choose Get Info from this same contextual menu, then change the Open With to be the TNEF application and click on “Change All..”
The TNEF application doesn’t seem to work for me. I have OS 10.4, and when I copy the winmail.dat file to the finder it takes on a Graphic Converter icon, but no files appear in the TNEF window that opens when I drag the file on the TNEF icon.
I have been unable to access Josh’s page to download the TNEF application. Safari keeps saying it can’t open the page. Help?
Thank you for your help, Dave. The applette at http://www.download.com/AkeeSoft-WMViewer/3000-2369_4-10383013.html?tag=lst-0-3 worked like a charm
Thank you so much for the TNEF tip. It works brilliantly.
I popped over to http://www.download.com/ and did a search for “winmail.dat”. Here are two that look like strong possibilities for you, Robert:
http://www.download.com/AkeeSoft-WMViewer/3000-2369_4-10383013.html?tag=lst-0-3
http://www.biblet.freeserve.co.uk/
I bet one of those will help you out!
Dear Dave – I read your solution to a MAC user about “winmail.dat” attachment files that drove him crazy. I have a professor who keeps sending us attachment with DAT extensions and it drives me nuts trying to decode them. So far no luck and I keep having to go beg for copies from class mates who can get decoded copies w/o any problems. Do you know of an app. similar to TNEF’s Enough for PC users. Apprciate your help. Cheers, Robert
In your solution for “winmail.dat” attachments are driving me nuts!, you said “indicate in their address book entry for you that you cannot receive Rich Text Format (RTF)”. I could not find that setting for address book entries.
Thank you.
Dave, thanks for this piece of information!
What a great title, too — so apt!
Cheers,
Harris