How to enable transport logging in Outlook

Microsoft Outlook supports the logging of the communications that occur between Outlook and various types of email servers. These logs can be helpful when you troubleshoot problems that affect the transfer of messages between Outlook and the email server.

Outlook can log the communications among Microsoft Exchange, Post Office Protocol version 3 (POP3), Simple Mail Transport Protocol (SMTP), Internet Messaging Access Protocol (IMAP), and Outlook.com servers.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To have us enable the mail logging option for you, go to the "Here's an easy fix" section. If you prefer to enable the mail logging option yourself, go to the "Let me fix it myself" section.

To enable logging, follow the steps for your version of Outlook.

1. On the File tab, click Options.
2. In the Outlook Options dialog box, click Advanced.
3. In the Other section, select the Enable troubleshooting logging (requires restarting Outlook) check box, and then click OK.
4. Exit and then restart Outlook.

1. On the Tools menu, click Options.
2. Click the Other tab.
3. Click the Advanced Options button.
4. Select the Enable mail logging (troubleshooting) check box.
5. Click OK to save the setting, and then return to the main Options screen.
6. Click OK.
7. Exit and then restart Outlook.

To enable logging for Outlook Connector version 14 in Outlook 2010, configure the following registry data.

• Subkey: HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Options\Mail
• DWORD: EnableLogging
• Value: 1
• Subkey: HKEY_CURRENT_USER\Software\Microsoft\Microsoft Office Outlook Connector
• DWORD: TracingLevel
• Value: 3

To disable logging for Outlook Connector version 14 in Outlook 2010, configure the following registry data.

• Subkey: HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Options\Mail

• DWORD: EnableLogging

• Value: 0

• Subkey: HKEY_CURRENT_USER\Software\Microsoft\Microsoft Office Outlook Connector

• DWORD: TracingLevel

• Value: 0

When you enable logging, the following registry data is configured.

Subkey: HKEY_CURRENT_USER\Software\Microsoft\Office\1x.0\Outlook\Options\Mail

DWORD: EnableLogging

Values: 1 = logging enabled, 0 = logging disabled

After you enable logging, all communications that occur between Outlook and the email server are written to a log file.

The log files are formatted as plain text. To find the log files, look in the following locations, depending upon your version of Outlook and also your version of Windows, if you are running Outlook 2007 or an earlier version.

The POP3, SMTP, and MAPI transport types are written to a single log file in the following location:

%temp%\Outlook Logging\Opmlog.log

The IMAP transport type is written to the following location:

%temp%\Outlook Logging\IMAP-usernamedomainname-date-time.log

For example: IMAP-user1wingtiptoyscom-03_23_2010-12_49_31_798.log

The Outlook Connector version 14 log file is written to the following location:

%temp%\OLC Logging\OLC-smtp_address-date-time.log

For example: OLC-guidopica@contoso.com-03_23_2010-16_13_10_803.log

The POP3, SMTP, and MAPI transport types are written to a single log file in the following locations.

• Windows XP and Windows 2000 C:\Documents and Settings\logon name\Local Settings\temp\OPMLOG.LOG
• Windows 98, Windows 98 Second Edition, and Windows Millennium Edition (Me) C:\Windows\temp\OPMLOG.LOG

The IMAP transport type is written to a log file in the following locations.

• Windows 2000

  C:\Documents and Settings\logon name\Local Settings\temp\Outlook Logging<NameOfIMAPServer>\IMAP0.LOG, IMAP1.LOG, and so on

• Windows 98, Windows 98 Second Edition, and Windows Me

  C:\Windows\temp\Outlook Logging<NameOfIMAPServer>\IMAP0.LOG, IMAP1.LOG, and so on

The Outlook.com log file is written to the following locations.

• Windows 2000

• C:\Documents and Settings\logon name\Local Settings\temp\Outlook Logging\Hotmail\Hotmail0.LOG, Hotmail1.LOG, and so on

• Windows 98, Windows 98 Second Edition, and Windows Me

  C:\Windows\temp\Outlook Logging\Hotmail\Hotmail0.LOG, Hotmail1.LOG, and so

Notes

• IMAP and Outlook.com accounts generate one log for each Send or Receive action that you perform on these accounts. (The log files are named Hotmail0.LOG, Hotmail1.LOG, etc.)
• If you have multiple Outlook.com accounts configured, the folders in which the logs are stored are named Hotmail, Hotmail 1, Hotmail 2, and so on.
• You may have to close Outlook so that the logs can be written to the log files.