Problem The problem applies to all versions of Outlook. With versions of Outlooks using MAPISP32.EXE, this process may hang. For more recent versions of Outlook, not using MAPISP32.EXE, the Outlook process itself may hang resulting in the error.
Possible workarounds when the error occurs The workarounds involve, among other suggested operating procedures, closing NEO and Outlook and checking the Task Manager for hanging processes of either MAPISP32.exe or Outlook.exe.
Steps if the problem occurs
If you don't already, start NEO after Outlook, or configure NEO to start with Outlook, ensuring to always open Outlook first and keep it open whenever NEO is open.
Ensure that Outlook is set as your default mail client.
Ensure that Outlook has not disabled NEO, for Outlook XP (2002) and Outlook 2003 only. To check this, go to Outlook 'Help | About Microsoft Office Outlook | Disabled Items button'. If NEO is disabled, enable it, close Outlook and then reopen Outlook.
This may be due to the MAPISP32.EXE process not closing down properly. Close Outlook and then with the Task Manager examine the 'Processes tab' for a MAPISP32.EXE process. If this process exists, place the focus (highlight) on the MAPISP32.EXE process and close it with the 'End Process' button.
If you are using a later version of Outlook, which doesn't use the MAPISP32, perhaps there is a hanging Outlook process. Close Outlook and then with the Task Manager examine the 'Processes tab' for a hanging Outlook process. If this exists, place the focus (highlight) on the Outlook.exe process and close it with the 'End Process' button.
Alternate steps if the problem occurs If you are not comfortable using the Task Manager then, as an alternative, close all applications and reboot your system.