What is the enable logging troubleshooting option

For diagnostic purposes, Microsoft Outlook for Windows 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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