MAPIFolderEvents_12_BeforeItemMoveEventHandler no longer firing in Outlook 365 RRS feed

  • Question

  • We currently have an Outlook VSTO Add-in that attaches to MAPIFolderEvents_12_BeforeItemMoveEventHandler

    This event has historically always been fired when a mail item is moved from one folder to another.  This has fired off an event that we respond to in order to perform processing on that mail item.  Recently there seems to have been an update to the Office 365 pro-plus version of Outlook that is causing this event to no longer be fired. I’ve reproduced this in the following version of Outlook…

    Version 1909 (Build 12026.20264 Click-to-Run)

    I’m not sure if this was the build that introduced the problem though.  I have a feeling it may be related to the update that occurred on November 27<sup>th</sup> of 2018.  Specifically the update to 'Keep working while moving messages.'


    I also have a sample add-in that I made that demonstrates the issue that I can provide.  It seems that if the reading pane is open or the email is open in another window the event will fire for that item.  But if the email is not currently open in either reading pane or separate window, the event will not fire and we will never be notified.


    public OutlookExplorerAdapter(Explorer explorer)
       explorer.FolderSwitch += explorer_FolderSwitch;
       CurrentFolder = (Folder)explorer.CurrentFolder;
       Explorer = explorer;
    private void explorer_FolderSwitch()
       /* update the current Folder */
       CurrentFolder = _explorer.CurrentFolder as Folder;
       CurrentFolder.BeforeItemMove += new MAPIFolderEvents_12_BeforeItemMoveEventHandler(CurrentFolder_BeforeItemMove);
    private void CurrentFolder_BeforeItemMove(object Item, MAPIFolder MoveTo, ref bool Cancel)
       MessageBox.Show("Before Item Move Executed");

    Is this the new expected behavior going forward?

    Tuesday, October 8, 2019 8:14 PM