Enable transport logging in Outlook 2007/2010

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

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

To enable logging, follow these steps:

For Microsoft Outlook 2010:

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 restart Outlook.
   Note When you enable logging, the following registry data is configured by Outlook.
   Key: HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Options\MailDWORD: EnableLogging
   Values: 1 = logging enabled, 0 = logging disabled

For Outlook 2007 and earlier versions:

1. On the Tools menu, click Options.
2. Click the Other tab
3. Click the Advanced Options button
4. Click to 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. Quit and restart Outlook.

Log File Locations:

For Outlook 2010:

1. On the Start menu, click Run.
2. Type the following text, and then click OK.

   %temp%

   • POP3 SMTP, MAPI logs

     %temp%\Outlook Logging\Opmlog.log

     The Opmlog.log file also contains some information that is related to the Outlook Connector.

   • IMAP logs

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

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

For Outlook 2007

1. In the Start->Run box, type "%Temp%" without quotation marks, and click Enter.
2. Open the olkas folder.

NOTE: It is very important to disable logging after the logs have captured the failed communication with the server. If you do not disabled logging, the logs continue to grow indefinitely.

Reference: http://support.microsoft.com/kb/300479/en-us