What is the Enable logging (troubleshooting) option?

For diagnostic purposes, Microsoft Outlook contains an option that turns on logging for certain Outlook features. These logs can be helpful for support staff who are troubleshooting problems.

In this article

Turn logging on or off

What information does logging record?

Log file locations

Administrator information

Turn logging on or off

Important:  Turn off logging after you complete your troubleshooting. If you don’t turn off logging, the log files continue to increase in size.

For Outlook 2016, Outlook 2013, and Outlook 2010   

  1. In Outlook, go to the File tab > Options > Advanced.

  2. Under Other, select or clear the Enable troubleshooting logging (requires restarting Outlook) check box.

  3. Exit and restart Outlook.

For Outlook 2007   

  1. In Outlook, go to Tools > Options.

  2. On the Other tab, select Advanced Options.

  3. Select or clear the Enable logging (troubleshooting) check box.

  4. Exit and restart Outlook.

Notes: 

  • After you restart Outlook, if mail logging is turned on, (Logging Enabled) appears in the Outlook title bar.

  • You may have to exit Outlook for data to be written to the log files.

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What information does logging record?

The logging option logs information about the following features:

  • Calendar transactions that are generated by Outlook features, by user actions, by the object model, or by the MAPI Calendar Table, including:

    • Inbox autoprocessing

    • Free/busy publishing

    • Reminders

    • Calendar item actions (creation, modification, or deletion)

    • Resource booking

    The main purpose of the calendar logging feature is to quickly identify situations where, for example, meetings are inexplicably deleted from a calendar folder.

  • Free/busy time changes

  • Offline Address Book

  • Transactions for the Messaging Application Programming Interface (MAPI), which is used with Microsoft Exchange, POP3, Internet Message Access Protocol (IMAP), Simple Mail Transfer Protocol (SMTP), and Lightweight Directory Access Protocol (LDAP).

    A unique log file is generated for each Send/Receive action that you perform on these accounts.

  • Communications with Exchange, POP3, SMTP, and IMAP servers.

Viewing the log files

Most log files are in plain text. To protect your data, the calendar log file is a binary file that can’t be read without a conversion process. Contact Microsoft Support for more information about calendar log files.

Log file locations

The log files are stored in subfolders of the Temp folder. By default, your Temp folder is located in your \AppData\Local folder:

  • c:\Users\username\AppData\Local\Temp

By default, the Local Settings and AppData folders are hidden.

To display hidden folders in Windows, do the following:

  1. In Windows, open Control Panel.

  2. Open Folder Options.

    • To locate Folder Options, in the search box at the top of window, type Folder Options.

  3. On the View tab, under Advanced settings, under Files and Folders, under Hidden files and folders, select Show hidden files, folders, and drives.

The following table shows the location and content of the various plain text log files.

Type of log file   

Subfolder    

File name   

Outlook 2013

Outlook 2010

Outlook 2007

Outlook Autodiscover

Temp

olkdisc.log

No

Yes

Yes

Exchange ActiveSync

Temp/EASLogFiles

datafilename.bin

datafilename.xml

Yes

No

No

Availability service

Temp/OlkAS

date-time-fb.log

No

No

Yes

Availability service, OOF, and meeting suggestion

Temp/OlkAS

date-time-AS.log

No

Yes

No

Protection rules

Temp/OlkAS

date-time-PB4S.log

No

Yes

No

Unified messaging

Temp/OlkAS

date-time-UM.log

No

Yes

No

Unified messaging configuration

Temp/OlkAS

date-time-UMCFG.log

No

Yes

No

Out-of-office

Temp/OlkAS

date-time-oof.log

No

No

Yes

Meeting suggestion

Temp/OlkAS

date-time-ms.log

No

No

Yes

Outlook calendar

Temp/OlCalLogs

OLKCalLog_date-time.etl

Yes

Yes

Yes

Transport

Temp/Outlook Logging

opmlog.log

Yes

Yes

Yes

SMTP

Temp/Outlook Logging

emailaddress-Outgoing-date-time.log

Yes

Yes

Yes

POP3

Temp/Outlook Logging

emailaddress-Incoming-date-time.log

Yes

Yes

Yes

IMAP

Temp/Outlook Logging

IMAP-emailaddress-Incoming-date-time.log

Yes

Yes

Yes

HTTP DAV

Temp/Outlook Logging

HTTP-emailaddress-date-time.log

No

Yes

Yes

Outlook Hotmail Connector

Temp/Outlook Logging

OLC-emailaddress-date-time.log

OLC-date-time.log

emailaddress.txt

No

Yes

Yes

Out-of-office

Temp/Outlook Logging

date-time-oof.log

No

Yes

No

Outlook profile

Temp/Outlook Logging

PROF_OUTLOOK_threadID_action_year.month.day_hour.minute.second.txt

Yes

Yes

No

Outlook sharing engine

Temp/Outlook Logging

Sharing Enginedate .log

Yes

Yes

Yes

Outlook-Windows Desktop Search indexing

Temp/Outlook Logging

datafilename.log

Yes

Yes

Yes

Outlook advanced ETW

Temp/Outlook Logging

Outlook-date-time.etl

Yes

Yes

No

Mailtips

Temp/Outlook Logging

date-time-mailtips.log

No

Yes

No

Free busy

Temp/Outlook Logging

date-time-fb.log

No

Yes

No

Outlook Sharing Engine

Temp/Outlook Logging

Sharing Enginedatetime-mailtips.log

Yes

Yes

Yes

Outlook first run process

Temp/Outlook Logging

firstrun.log

Yes

Yes

Yes

Administrator information

As an administrator, you can use the registry to turn logging on or off, and you can also deploy logging settings to users.

  • For information about how to turn logging on and off by using the registry, see Microsoft KB 831053.

  • Default Outlook logging settings can be configured in the Office Customization Tool (OCT) on the Modify User Settings page, or you can enforce the settings by using the Outlook Group Policy template (Outlk15.adm) in the Local Group Policy Editor.

    Important: Because of performance and security reasons, we don’t recommend that you deploy the logging feature. Turn on the logging feature only when needed.

    To enforce logging settings for Outlook users, do the following:

    1. In Group Policy, in the Outlook 2013 policy template Outlk15.adm, under User configuration\Administrative templates\Microsoft Outlook 15\Tools | Options\Other\Advanced, double-click Enable mail logging (troubleshooting). Select Enabled to enable configuring the settings.

    2. Select or clear the Enable troubleshooting logging (requires restarting Outlook) check box.

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