How to configure the default message class for new items in an Outlook folder

Original KB number:   2697986

Summary

Some custom or third-party solutions change the default message class that is used when new items are created in a Microsoft Outlook folder. The message class is associated with each item in a folder. Additionally, it defines which form to display when the item is opened. If a custom solution changes the default message class for an Outlook folder, uninstalling that solution may not reset the folder's new-item message class to the default configuration. In this situation, various issues can occur in Outlook, because the default new-item message class for a folder was changed from the default value. For example, if you select the New button to open a new item for the folder, the form does not seem to be the original default form that was installed by Outlook.

If you are not using a custom Outlook solution that requires a custom message class for new items in a folder, we recommend that you use the default message class for at least the following primary Outlook folders:

  • Calendar
  • Contacts
  • Tasks

More information

The following table lists the main default folders in Outlook in which custom messages classes are sometimes found. The second column in the table provides the default message class that is used for the folder.

Folder Default message class
Calendar IPM.Appointment
Contacts IPM.Contact
Tasks IPM.Task

To determine the currently configured default message class for new items on a folder, follow these steps:

  1. Right-click the folder, and then select Properties.
  2. Select the General tab.
  3. Inspect the value that appears in the When posting to this folder, use list.
  4. If you want to change the default message class for new items that you add to the folder, select the When posting to this folder, use list, and then select the appropriate message class for the folder. (See the table.)

Note

If you already created items in the folder by using a custom message class, changing the When posting to this folder, use value does not change the message class on these existing items. When you change the When posting to this folder, use value, only items that are created after the change will use the newly configured message class.