What is OLK File Extension?


OLK was introduced by Microsoft. It is an acronym for Outlook Address Book. OLK file extension is supported by Mac Outlook email app to efficiently hold contact info of personal and commercial. It holds names, addresses, numbers, email IDs and much more. The file extension is identified as .olk. It has versions or types which one should know to use the extension properly.   

The 2011 version of Outlook for Mac saves emails in two files i.e. OLK14MESSAGE and OLK14MSGSOURCE.

The 2016 version of Outlook for Mac uses OLK15MESSAGE file.

OLK14Message file is capable of saving header info of emails

OLK14Msgsource file has the capacity of saving entire email body info

OLK14Category file creates the categories in Personal, Family and holiday.

OLK14Event holds info of events in form of time, date, visitors.

OLK14Contact file is capable of keeping the record of names, emails and phone numbers.

OLK14Signature file saves mail signature of Mac outlook profile in HTML format.

OLK14Mailaccount holds user's account info.


It falls under the category of Database files.


It is taken care by Microsoft.

Supportive Apps

MAC Outlook 2011 and other versions support OLK.

OP Support

Only MAC users can run the app.


The file location is depended on the type you are using.

OLK14Message – Username\Documents\MicrosoftUserData\Office2011Identities\MainIdentity\Data Records\Messages\OM\OB\OT

How to access OLK File Extension

An OLK file can be accessed on Mac MS Outlook. Users can open an OLK file on free or paid version of tools.