I have searched high and low and done everything suggessted when it comes to winmail.dat attachments. However, I cannot find a solution to something that just started happening 10 days ago. Running Exchange 2010 all SP and rollups. Users have outlook 2010. As stated 10 days ago, a couple users started getting emails with winmail.dat attachments from outside emails. These other companies are using exchange 2003, 2007 and 2010 (various companies). When I am copied on the emails (testing solutions for this problem) all attachments come through normally, but the 2 users that I am working with are still getting winmail.dat attachments. Figured I'd eliminate outlook and just check OWA. The 2 users OWA accounts (outlook is closed and not running at all at this point) still have the winmail.dat attachments in OWA. This is the part that is most confusing to me as it seems like a issue with their mailboxes as it is now happening without outlook involved. In addition to the RTF settings on the exchange server, HTML/plain test settings on the clients, we have also removed any rules and deleted the contacts in the users contact folder just to be sure there isn't anything funky there. Also checked with the senders, they are all using outlook 2007 or 2010 and sending emails as HTML and as mentioned earlier, all these companies are using exchange 2003 or later. What am I missing?

Yes, it's consistent for these 2 users. I have enabled tracing so we'll see what we get. I don't see anything strange in the header info on any of the emails. I can post some of them here but is there anything I should be looking at specifically?

That's strange, that typically happens to contacts but not MEUs. If you get stumped, I'd be inclined to move the mailbox to another store as this will create a new mailbox. (incase there is mailbox corruption)James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

After send mail to both of the problematic user and the working user, you can then compare two copies, and seek for the difference. Agree with Chong. If the message is identical, the issue would be related to the problematic mailbox itself, moving mailbox could fix certain corruptionPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

James and James, Headers look identical. Tracing is not really turning up anything compared to tracing on "normal" messages that aren't getting the winmail.dat. Your suggesstion to move to another store was in the back of my head, but I was waiting to see if someone else felt that course of action was the next step. I'll do that and report back. Thanks

Did moving the mailbox solve the problem?

i need to know what solved this problem. I am having the same type of issue. We are running Exchange 2007 with Outlook 2010 clients and one person will receive winmail.dat files while others copied on the same email will receive a normal email with a Word document attached. Of course I can use a read on it and it shows the winmail.dat file properly but this is not the fix.George

bumping for a solution!!! also having this problem randomly

I too am having these exact same problems at my organisation. We are on Exchange 2010 with clients running Outlook 2010. A handful of users are getting winmail.dat files instead of the attachments, other users on the same exchange server will receive the same email with the attachment as it should be (e.g. a .doc or .pdf etc.). It's really frustrating for the users it's happening to and they are getting on at me to sort it but there doesn't seem to be a solution!!!! Please, has anyone been able to resolve this? Note that I also did move one of the affected users mailboxes to a new store but it didn't fix it.

Yes, changing "use MAPI rich text format" to NEVER may be one solution. But settings in Personal Contacts might also be brought into play. See the thread below: winmail.dat http://social.technet.microsoft.com/Forums/en/exchangesvrgeneral/thread/19e628ae-9cd4-490d-bc87-b225f866e259MCTS: Messaging | MCSE: S+M

OK I think i have it! I noticed that the email address that we were having issues receiving attachments from all had a contact card created for them in exchange. I went into the contact card for these external email addresses and changed "use MAPI rich text format" to NEVER. i believe that the because these email address were contacts in exchange, no matter what the outlook setting was, when the clients sent the messages off to the server for delivery, Exchange would override the setting with the one in the contact card. Let me know if this helps anyone else. My issue is with an exchange 2007 mailbox - not a mail contact. Has anyone a solution for me?

OK I think i have it! I noticed that the email address that we were having issues receiving attachments from all had a contact card created for them in exchange. I went into the contact card for these external email addresses and changed "use MAPI rich text format" to NEVER. i believe that the because these email address were contacts in exchange, no matter what the outlook setting was, when the clients sent the messages off to the server for delivery, Exchange would override the setting with the one in the contact card. Let me know if this helps anyone else. My issue is with an exchange 2007 mailbox - not a mail contact. Has anyone a solution for me? Yes, we need to understand that the issue here IS NOT external recipients getting winmail.dat files. The issue here is that internal clients running exchange server mailboxes are receiving winmail.dat files from incoming mail and that it is happening to some users but not others on the same exchange server.

I have also seen this on Exchange servers. More often in the days og Exchange 5.x / 2000 / 2003 than now. Have these senders send the messages in Plain Text. That should work. Winmail.dat attachments are included in received e-mail messages in Outlook Last Review: March 7, 2011 - Revision: 5.0 http://support.microsoft.com/kb/278061MCTS: Messaging | MCSE: S+M

OK I think i have it! I noticed that the email address that we were having issues receiving attachments from all had a contact card created for them in exchange. I went into the contact card for these external email addresses and changed "use MAPI rich text format" to NEVER. i believe that the because these email address were contacts in exchange, no matter what the outlook setting was, when the clients sent the messages off to the server for delivery, Exchange would override the setting with the one in the contact card. Let me know if this helps anyone else. My issue is with an exchange 2007 mailbox - not a mail contact. Has anyone a solution for me? My issue was internal users receiving winmail.dat from external contacts, to clarify, i created contact cards for specific email address that i wanted to include in a distribution list. I believe that the settings in that contact card adjusted the formatting when receiving email from those addresses, that's why changing use MAPI rich text to "never" resolved my issue. are you sure that all the email address in question do not have a contact card somewhere in exchange?

"..are you sure that all the email address in question do not have a contact card somewhere in exchange?" ..how do I determine that?

under recepiant configuration look in mail contact

under recepiant configuration look in mail contact There's no mail contacts listed under recipient configuration on my exchange management console, any other suggestions?

under recepiant configuration look in mail contact ..yeah that is what I thought you meant but as I said, it is the exchange mailbox not a mail contact that is receiving these attachments. I don't understand why or how you would have a mail contact for an exchange mailbox. I only have 1 mail contact and that is so I can redirect the mailbox to an external domain email address (this user is not affected).

I only have 1 mail contact and that is so I can redirect the mailbox to an external domain email address (this user is not affected). It looks like our issue was different then yours, we were receiving winmail.dat attachments to our exchange mailboxes from ONLY the external address that we created contact cards for. (it would seem that you and i created these contact cards for the same reason). Users that did not receive emails regularly from those address that were associated with an exchange contact card were not affected.

under recepiant configuration look in mail contact There's no mail contacts listed under recipient configuration on my exchange management console, any other suggestions? are you using an MMC or are you directly working on the exchange server?

under recepiant configuration look in mail contact There's no mail contacts listed under recipient configuration on my exchange management console, any other suggestions? are you using an MMC or are you directly working on the exchange server? I'm working directly on exchange server, I don't have any mail contacts listed under recipient configuration. This is getting to be quite a problem in our organisation with colleagues getting increasingly irritated by receiving winmail.dat files. I had a typical example this morning where one colleague received an email from an external sender but got a winmail.dat attached instead of 5 pdf files which should have been attached. We got the sender to resend the email with attachements to my address (on same exchange server) and the attachments came through no problem. So frustrating, does anyone have any further suggestions to try?

under recepiant configuration look in mail contact There's no mail contacts listed under recipient configuration on my exchange management console, any other suggestions? are you using an MMC or are you directly working on the exchange server? I'm working directly on exchange server, I don't have any mail contacts listed under recipient configuration. This is getting to be quite a problem in our organisation with colleagues getting increasingly irritated by receiving winmail.dat files. I had a typical example this morning where one colleague received an email from an external sender but got a winmail.dat attached instead of 5 pdf files which should have been attached. We got the sender to resend the email with attachements to my address (on same exchange server) and the attachments came through no problem. So frustrating, does anyone have any further suggestions to try? my last suggestion would be to make sure that you whitelist the sender domain on any firewall/spam filter/content filtering. Make sure that nothing touches the email through transport until it gets to the mailbox. outside of that, im not sure...

how was that solved?! i mean the problem posted on top i am having exactly the same and was reading through the above until i reached the end with nothing!!!

I don't think there is a definitive solution yet. Hopefully, Stoop will come back with Microsoft's answer. OWA client *RECEIVES* winmail.dat attachments http://social.technet.microsoft.com/Forums/en/exchangesvrclients/thread/207469f1-9f2a-49dc-8a4b-d8b70e42c855 See also this thread: Exchange 2010 receiving winmail.dat http://social.technet.microsoft.com/Forums/en/exchange2010/thread/d3f58f62-2f23-484a-a641-c6ed1577bbdbMCTS: Messaging | MCSE: S+M

Has anyone gotten a good answer from Microsoft on this issue? We are now experiencing this with a few users. It seems to be with large (>2MB) .ppts and it happens from internal users to internal users. i have tried the hotfix, we have made sure they are sending in either HTML or plain text, but it is still happening. It also seems to be spreading. More users are having the issue. I am planning on calling MS on Monday, but I am hoping to avoid that.

We are running into this now where some users are receiving winmail.dat from external users and other users are not, on the same email. Currently using Exchange 2007 and Outlook 2010. To be clear asking senders to change their settings is not a solution.

I'm joining the chorus, because this thread is closest to my issue as any other I've found. I also have a few users that are getting e-mails that are supposed to have attachments (*.docx, *.xlsx, *pptx, calendar invites, ...) that are converted to winmail.dat files. I've had senders cc: the users work e-mail (which is getting the winmail.dat), my e-mail (same exchange server as user, which gets the message just fine), and to the users personal e-mail (Yahoo, hotmail, ...; which arrives just fine). The users OWA account also gets the winmail.dat file. We're running Exchange 2007, SP3, Rollup 7 on a Windows 2008 Standard Server that is also up to date. We run Symantec Mail Security for MS Exch (6.5) for antispam/antivirus and it is up to date. I am running Windows 7 at the desktop, while the affected users are still on XP. This particular issue also started happening just recently. In the past I've needed to update the SMSME app. But it's up-to-date, along with everything else in the chain that I have control of. To reiterate what many, many, many posts have stated: ASKING THE SENDER TO USE PLAIN TEXT IS NOT AN OPTION! The sender is using exchange/outlook and we are using exchange/outlook. The two systems should be talking not only apples to apples, but Granny Smith Apples to Granny Smith Apples. Instead they are talking apples to broccoli. The senders (there are multiple 3rd party organizations we are having problems RECEIVING email from) all are using Exchange 2010, while we are using Exchange 2007. It does not appear that I am having problems with e-mails from exchange 2007 organizations, only from exchange 2010 organizations. As stated before, some of my users are getting the SAME e-mail fine, while others are not; and yahoo, hotmail, ... are also getting it fine. A long term resolution would be appreciated.

Any news on this? I have the same issue outside senders sending from Outlook to my Exchange and getting the Winmail.dat. also the user can ask the sender to resend same message and it comes through just fine. So again to make sure we stay clear this is OUTLOOK to OUTLOOK trying to find a solution to this would be great to hear something close to a solution.

Figured I'd chime in as I also have this exact same issue. An external user (using Outlook, not sure on version) sends one email with attachments to two people in our Exchange 2010 environment. Both are using Outlook 2010. One receives the two 1.5MB PDF's, the other receives one 3MB Winmail.DAT. I have requested that the external sender remove a contact they may have in their Outlook for the user on our end that is receiving a winmail.dat, as that is the only thing I can think of that may be causing the issue. It is isolated to this one sender, so there must be something unique happening between the sender/recipient. Anyway, I'll post back once they can test this out.

Same issue here... just started happening with using Secure Email solutions with message labs. I tried to replicate the issue, but to no avail. Our situation is with a 315K PDF and mostly with gmail recipients. I'm diggin in more with all the information in the thread and will report back if we get closer to identifying root cause, or a solution. We do have one solution that seems to fit the profile: If we remove the contact from the address book cache, and then re-add it, it works. However, we can't keep this interim fix as a long term solution as our customer services has way too many emails of clients to be doing this. The interesting thing for the error is the email comes through ok, its onlt the PDF that is replaced with winmail.dat.

I think this is the answer for your problems.... It did help me. I thought it would be easier to visualize the solution using a printscreen from Exchange. In Microsoft Exchange Server 2010, select Microsoft Exchange On-Premises, select Organization Configuration, select Hub Transport, select the Properties for Default (or Domain name you have defined), select Never Use under Exchange Rich-text format. Save. Links: http://social.technet.microsoft.com/Forums/sa/exchange2010/thread/10df55b7-1ea4-4539-96a1-8c2b6540f202 http://support.microsoft.com/kb/138053 http://support.microsoft.com/kb/958012 (Danish) Hope this can solve your problems Regards JOM-ITjom