MSGMicrosoft Outlook Email Format
MSG is a file format used by Microsoft Outlook and Exchange to store email messages, contact, appointment, or other tasks. Such messages may contain one or more email fields, with the sender, recipient, subject, date, and message body, or contact information, appointment particulars, and one or more task specifications. The properties that constitute the Message object, including are also a part of the MSG file.
XPSOpen XML Paper Specification
An XPS file represents page layout files that are based on XML Paper Specifications created by Microsoft. This format was developed by Microsoft as replacement of EMF file format and is similar to PDF file format, but uses XML in layout, appearance, and printing information of a document. It is, in fact, more justified to say that XPS is an attempt on PDF, but couldn't get enough popularity as owned by PDF for a number of reasons.