log

https://msdn.microsoft.com/en-us/vba/outlook-vba/articles/save-a-form-with-the-item-one-off-forms

https://msdn.microsoft.com/en-us/vba/outlook-vba/articles/item-types-and-message-classes

https://msdn.microsoft.com/en-us/vba/outlook-vba/articles/change-the-icons-associated-with-your-form?f=255&MSPPError=-2147217396

http://www.outlookcode.com/threads.aspx?forumid=2&messageid=15991

Sub ok()
' Change the following line to your new Message Class
NewMC = "IPM.Appointment.Myform"
Set CurFolder = Application.ActiveExplorer.CurrentFolder
Set AllItems = CurFolder.Items
NumItems = CurFolder.Items.Count
' Loop through all of the items in the folder
For I = 1 To NumItems
  Set CurItem = AllItems.Item(I)
  ' Test to see if the Message Class needs to be changed
   If CurItem.MessageClass <> NewMC Then
   ' Change the Message Class
   CurItem.MessageClass = NewMC
   ' Save the changed item
    CurItem.Save
End If
Next
MsgBox "Done." & NumItems
End Sub

http://www.outlookcode.com/article.aspx?ID=39