EWS.FindItems returning more items than expected from your inbox?

In my inbox, I only have 5 emails (4 unread, as shown in the picture, and one already read).

Also, in each of the search folders such as unread emails, follow-ups, etc. I have a lot of emails (over 1000) and the oldest is dated 2011 (date / time received).

When doing FindItems, I find an even older email that has a property DateTimeReceived

worth 2004-08-15?

The only thing I can think of is that using the FindItems method also retrieves emails from archived ones, right?

getInboxItems

private FindItemsResults<Item> getInboxItems() {
    var inboxFolderId = new FolderId(WellKnownFolderName.Inbox
                                    , mailboxConfiguration.MailboxName);
    var allItems = new ItemView(int.MaxValue) {
        Traversal = ItemTraversal.Shallow
        , PropertySet = new PropertySet(EmailMessageShema.DateTimeReceived
            , EmailMessageSchema.LastModifiedTime)
    };
    var foundItems = Service.FindItems(inboxFolderId, allItems);
    return foundItems;
}

      

        
        
        
      

    

This returns about 40 emails and among them the oldest obsolete email from 2004 was found, which I can't find anywhere in any mailbox folder when accessing it through Outlook.

Short question: What's going on?

I cannot find anything on the internet for this.

UPDATE

After further investigation, the provided sample code is proven to be opaque according to these simple steps:

• Select the Inbox folder, right click and select Properties

2. Inbox tab, General tab, click Show Count of All Items (may differ from the actual English version as I translated myself as I thought it might be in English).

3. Now back to the Inbox, we can see that there are actually a lot of items.

So, it seems that my code is correct, and although this total count reports 35 when the Inbox is selected, I only see the five aforementioned emails.

I thought it might have something to do with archived items and I was confirmed that archived emails are moved to an external archive tool and removed from Exchange, which leaves me clueless.