The OLM file came into existence when Microsoft has introduced the MS Outlook for Mac Operating System. It is the master repository of Mac Outlook but it is not created by it by default. There are two ways to generate the OLM file simply drag and drop the MAC Outlook folders or exporting the network part of the can also be exported as OLM file. These are the database files that contains all the user outlook folders such as inbox, calender, contacts, tasks. Olm is mail client that stores the whole data in a single file. Olm file should not exceed above 2gb, though there is no predefined size for it. If olm fize size exceeds beyond 2gb than corruption might occurs.
Types of OLM File :-
There are two types of olm files available on mac outlook 2011 email application
Outlook archive .olm » These files are hard to export to other applications
OLM » These files are easy to export and stores and manage mac outlook 2011 database in .olm file format
OLM file Can only open up with Mac Outlook version 2011 and 2016
Application/octet-stream
Microsoft Corporation is the developer of MAC Outlook 2011 and its associated olm file format
MAC Outlook 2011
~/Documents/Microsoft User Data/Office 2011 Identities/Main Identity/