Hi,

I have seen a few posts regarding PST Capture converting attachments to winmail.dat files, however none have ever had a satisfactory resolution.

We were using a hosted Exchange 2013 environment and are now moving to Office 365.

Our previous email provider have exported PST files of all our mailboxes using Powershell (I don't know the exact cmdlet or syntax they used but I'd imagine this is fairly standard).

If we open the PST in Outlook all messages are there and are working.  If we import the PST using Capture Tool emails that contained attachments have now been converted to winmail.dat.

Various posts have mentioned about making sure the emails are in RTF but none have explained how we can confirm that in a PST after it has already been exported. Having our previous email provider export the PST files again isn't really an option for us at this point.

Myself and a colleague have now been working on trying to get our email migrated to Office 365 for a week now and we have had almost zero success at all and we have over 200 mailboxes to migrate.

We have also tried delegating mailbox access to ourselves in Outlook and importing the PSTs through the native Outlook import/export wizard but this has proven unreliable and full of problems in it's own rights and we've all but given up now on both supposed, and I use the term very loosely, 'solutions'.

Any assistance in getting a full resolution to our import issues would be hugely appreciated.

Hi,

Based on my knowledge, to check the format of messages in PST, we can open this PST in Outlook 2013/2010, then open one message contained attachments. On the top of this message, check the format in the parenthesis after the title of this message.

Hope the following documents might be helpful for you

https://technet.microsoft.com/en-us/library/hh781036(v=exchg.141).aspx

Best Regards.