emailed .pdf files are gibberish

I am having a problem with a new computer running Windows 7 Professional and Outlook 2007 where all .pdf attachments are not going through as attachments but as garbage within the body of the email.  The .pdf are being generated by my practice managment software.  When I open the messages back up in Outlook from sent mail - they look okay, but obviously the recipient is not getting them that way.  Is this a .pdf setting problem?  Outlook problem?  Server problem?