I have an office with users using office 2007 and 2010 on Exchange 2010. The users get regular email from a client with a pdf the users using 2007 can see the pdf the 2010 users get an attachment winmail,dat. All the reading I've done for the problem has to do with the sender and asking them to not send out the message in RTF but if it were a problem on the senders side why can my 2007 users see it. And also I have no control on the Outlook settings for a user at another company. There has to be something locally I can do to receive these files.