Winmail.dat

[Jaytrue]

Hi all,

I spent most of Friday trying to solve a problem that has recently surfaced with a some of our customers when I send emails with attachment to them.

These guys have Apple Mac's/iMac's and have been receiving emails with both .jpegs and .pdf's from us for years with no problem, but now in the last few days the dreaded winmail.dat attachment is appearing.

There have been no updates or software changes that I am aware of.

I am using Office365 Outlook directly from the BT server, so no Outlook software on my computer, therefore I have no option to turn off the RTF. I have also tried the 'set RemoteDomain' and everything seems to go fine until the last command line that actually tells the remote server TNEF flase. - Possibly something only a BT admin can do?

I have even tried sending emails to these customers in plain text, email received fine....attachment still states winmail.dat!

So I am now stuck with us not being able to send attachements to any of our customers who have Apple computers......any thoughts or pointers would be much appreciated.

Thanks and kind regards,

Justin

[WNeale]

I have been exactly the same problem - any solutions?

[markp]

Hi All,

This is a know issu. Current investigations indicate that Transport Neutral Encapsulation Format (TNEF) may be the root cause. Microsoft engineers are currently working to provide global fix for the problem. Workaround fixes can be applied by disabling TNEF on the senders or receivers mail client. Microsoft brief to do this can be found on the following link

Markp

[M-CLEANUK]

I have this issue and have clicked on your link.

It doesn't work

[strebori]

Having the same issues. It's frustratingly intermittent. Some of the recipients are Apple users, but not all. Some are on Windows 10, but not all. As it's only become an issue in the last couple of weeks, has there been some update to the BT version of Office 365 that has triggered it?

[SMountier]

We are also having the same problem - and similarly it started just after Easter.

My colleague spent 25 mins waiting on BT Chat to be told it was a known problem between them and Microsoft... They had no idea when it would be solved!!!! I suggested that the problem was TNEF from checking other email forums and all they needed to do was get their administrator for btconnect.com to set the defaults to NOT send out as TNEF format.. but understandably the BT guy could only say he would mention it!

I know this IS the problem as when we send attachments to gmail accounts it is fine as they can decode TNEF formats.... Surprisingly outlook 2010 and some other Microsoft own versions cannot!!!

Hopefully this will be resolved real quick as it does not encourage business clients to say the least!

I've told them they can save the winmail.com file and convert via www.winmaildat.com but they are understsandly reluctant to do so on a third party software.

Stephen

[hallwod]

We have the same problem but some recipients using Outlook 2010 (Windows) receive the attachments as intended. I have noticed that even though the messages are originated in HTML at recipient level they arrive in Plain Text.

For me this just confirms the problem is at the BT server but we users are helpless to do anything. Come on BT the interim solution is simplest just action!

[strebori]

Just had an email response from BT on this which advised me Microsoft have proved a link to a work around "whilst they are investigating this issue."

"Microsoft are still working on this issue and look to have identified the root and anre now working on a complete resolution. They have not as yet supplied a timescale with regards however."

The link is:

https://support.microsoft.com/en-us/kb/2487954

I've tried it and not managed to do anything, but I'm no IT administrator - if anyone has better luck and can explain it in simpler terms, please do!

[SMountier]

This is NOT a Microsoft workaround for the BT problem for Clients. It is an instruction that has been out there for a long time for Domain administrators (i.e. BT in our case) to correct their Domain settings specifically the last part:-

Set-RemoteDomain {Default/-Identity <name of domain>} -TNEFEnabled $false

 If BT will signon to PowerShell and set their default to send out as TNEFEnabled $false this would solve the problem. The trouble is it would seem no-one at BT are prepared to do so!!  Why?

Set-RemoteDomain Default -TNEFEnabled $false

As we re not the administrators we cannot as clients do so.

Can BT please look at their own forum??  And give a constructive response and NOT hide behind Microsoft PLEASE!

Stephen