.OLK15MESSAGE File Extension

Outlook 15 Message Header

Developer Microsoft
4.0  |  2 Votes

What is an OLK15MESSAGE file?

An OLK15MESSAGE file is an email data file created by Microsoft Outlook 15 (Outlook 2016) for Mac. It contains an email's header information; it does not contain the email's body content. Outlook for Mac uses OLK15MESSAGE files to show message overviews.

More Information

Microsoft Outlook is an email and calendar app available for Windows and macOS. Microsoft Outlook 15, a Mac version of Outlook released in 2014, saves local copies of users' email messages in a series of OLK15 files.

For example, an email that includes body content and an attachment would have its data saved in three separate files, an OLK15MESSAGE file, an .OLK15MSGSOURCE file, and an .OLK15MSGATTACH file. Outlook 15 uses these files to load messages more quickly when a user is browsing their email.

The OLK15MESSAGE file contains the email's header content, including the email's To, From, and Subject information. Outlook 15 saves OLK15MESSAGE files in the following directory:

~/​Library/​Group Containers/​UBF8T346G9.Office/​Outlook/​Outlook 15 Profiles/​Main Profile/​Data/​Messages

How to open an OLK15MESSAGE file

OLK15MESSAGE files are temporary files and not meant to be opened by users. However, you can use Gladwev OLK14 Message Recovery Tool (Mac) to recover the message data your OLK15MESSAGE files (and other OLK15 files) contain.

Open over 400 file formats with File Viewer Plus.Free Download

Programs that open or reference OLK15MESSAGE files

Verified by FileInfo.com

The FileInfo.com team has independently researched the Outlook 15 Message Header file format and Mac apps listed on this page. Our goal is 100% accuracy and we only publish information about file types that we have verified.

If you would like to suggest any additions or updates to this page, please let us know.