Hi guys, I have a user who's been receiving emails from an external client with attachments converted into bin files. We are on MS Exchange 2010 SP2 and Outlook 2010. I contacted the sender and found out that they use MS Exchange 2007 (not sure about SP) and Outlook 2010. I asked the sender to send another message with the attachment in question, a 6 MB MS Word document, to both the affected recipient and me, and the affected user received a bin file again and I received an MS Word doc file. If the user tries to open the file and selects MS Word, it opens normally. The file shows as bin even when accessed through OWA, directly on Exchange. Any idea what's going on? Thanks Zoran

Hi, Please try to verify if the issue would occur when user access mailbox via OWA from other machine. If no, then I recommend you to try to disable all the 3rd services from windows system configuration. Also please check the applications which have been installed on the machine. By the way, do you have anti-spam/anti-virus related application installed? Please check what you will have under HKEY_CLASSES_ROOT\.bin. From my lab, I only have PersistentHandler which value data is 098f24... Xiu Zhang TechNet Community Support

Hi Xiu, I exported the whole mailbox to a PST file and attached it to my Outlook. Then I found the attachments in question and they were there as bin files, so I guess that's how they are stored on the server. There is no AV software on Exchange, but only on clients. We do have an externally hosted email filter, but I guess if the filter messed up with the message that was sent to both the affected user and me, then I would have received the attachment as a bin file as well, and that didn't happen. There is also a Notes server in-line, working as a gateway (some old stuff), but again it would either affect all recipients of a message or none. It was a single message, sent to 2 recipients. It seems that the file was converted on our Exchange server, but it's confusing why it's happening to one recipient and not the other. With this particular issue, 2 recipients are affected and only when receiving messages from a specific external user. Though, the service desk said it happened before. The registry key is the same, PersistantHandler {098f2470-...} on both my and the affected client's machine. Thanks Zoran

Hi, What is the message system for the external user? Please try to forward the message and then verify the attachment. Besides, I think we may have to contact the email support from external user organization to help to collect the pipline tracing log if they use Exchange Server. Xiu Zhang TechNet Community Support

Hi Xiu, Thanks for you help. I will talk to my manager and see if she wants to log a job with Microsoft in order to troubleshoot this issue further. I just thought it would be a good idea to check on discussions first and see if anyone experienced a similar issue before. If I resolve the issue, I will post the solution here. So for now, please close the job. Thanks Zoran

Hi Xiu, I asked the sender to check with his admins the rich text format setting at their server side (Exchange 2007). So they set it to Never use (under properties of the default object under the remote domains tab) and it fixed the issue. Organisation Configuration > Hub Transport > Remote Domains > right click the object Default > click on Properties > select 'Never use' under Exchange rich-text format I have seen this TNEF issue before on Exchnage/Outlook 2000 and 2003, where an attachment sent either internally or externally arrives as a DAT file or is not visible thorugh Outlook, but is visible and accessible through OWA. But I have never seen it gets converted to a BIN file. HTH someone else. Zoran