Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ your_Outlook_version\Outlook\SchedulingInformation\.Note: If you're using a 32-bit version of Outlook on a 64-bit version of Windows, enter %systemroot%\syswow64\regedit instead in the Run dialog.
Note: Alternatively, press the Windows key + R. For details, go to Using a 32-bit version of Outlook on a 64-bit version of Windows. Note: If you're running a 32-bit version of Outlook on a 64-bit version of Windows, you'll need to add these registry keys in the correct location for 32-bit applications. Add the following keys to override the default timeout values: You can extend this period by modifying your Windows registry. By default, the timeout is hard-coded to occur at 90 seconds. The message remains unsent in your Outbox. If you send a message with large attachments over a slow connection, the connection can time out.
