File with an .OLK14MESSAGE extension contains a header of an email stored by Outlook 2011 program for Mac OS. The content of the message is being stored within a corresponding file with the OLK14MSGSOURCE extension. These formats are proprietary, encoded, although if opened with a simple text editor, sometimes, fragments of a text readable for a man can be seen.

.OLK14MESSAGE files enable to view a draft of a message while browsing mail via Outlook. Such files can be also opened manually by double-clicking. The program, while downloading the mail will automatically store copies of messages within user’s directory: [user]/Documents/Microsoft User Data/Office 2011 Identities/Main Identity/Data Records/Messages/.