According to documentation, the MailItem.FlagStatus property in Outlook is deprecated. So what does Outlook use to mark a mail item as "in progress" or "waiting on someone else" when said item is flagged and thus appears in the to-do list? I'd like to programatically change the status of items in the to do list, but only Task Items have the Status property and I can't figure out the correct equivalent for mail items.

While Programmatically setting a MailItem's followup flag to complete? is related, I don't believe it answers my question. The Flag Request property appears to document the associated follow up action, rather than assigning one of the standard statuses used for Task Items (Not Started, In Progress, Waiting on Someone Else, Deferred, Completed).

What I'm trying to do is this: outlook's to-do view allows you to set the Status of both task items and flagged mail items.

You can also set the status of task items programmatically by assigning to the Status property, e.g. myTaskItem.Status = olTaskWaiting sets the status to "Waiting on Someone Else". I'm trying to figure out how to do the same thing to mail items. I have attempted to do this via myMailItem.FlagStatusand been unsuccessful: while Flag Status does correspond to some of the statuses, it does not do so uniquely (0 seems to equal both In Progress and Deferred). Since Flag Status is deprecated anyway, I thought there might be some other way to set these values.

My Progress: This page has someone with nearly exactly the same question I do, and the answer seems to suggest that the "status" property is added directly to the mail item when it is flagged as a to-do. However, I'm not sure under what name task status has been added. Item.Status gives me the error "Object doesn't support this property or method", and Item.UserProperties("Status") also gives an error.