我试图在Outlook中循环浏览电子邮件，废弃唯一的ID号，并将它们连接为一个字符串。
每封邮件包含多个不同的ID，这些ID在整个电子邮件中成倍增加，如下所示：

ID 1111, ID 2222
ID 1111, ID 33333, ID 2222
ID 1111, ID 2222, ID 444, ID 33333
ID 2222, ID 1111

那么预期结果将是（排序）：

ID 444, ID 1111, ID 2222, ID 33333

这是我的代码。

Sub Scrap_IDs()

Dim olApp As Outlook.Application: Set olApp = New Outlook.Application
Dim olFolder As MAPIFolder: Set olFolder = olApp.Session.GetDefaultFolder(olFolderInbox).Folders("Folder_name")

    Dim olMail As Variant: For Each olMail In olFolder.Items
        Dim mBody As String: mBody = olMail.Body
    
        With olMail
        ' Scrap all IDs using regex
             With New RegExp
                    .Global = True
                    .Pattern = "ID[ \d]+"
            
            Dim MatchID As Object: For Each MatchID In .Execute(mBody)
                    Dim i As Long: Dim arrMatchID(): ReDim Preserve arrMatchID(i)
                    arrMatchID(i) = MatchID.Value
                    i = i + 1
                Next
            End With
            
        ' Remove duplicates from array
            Dim RemArrDups As Variant: RemArrDups = WorksheetFunction.Sort(WorksheetFunction.Unique(WorksheetFunction.Transpose(arrMatchID)))
    
        ' Concatenate array items
            Dim IDs As String: IDs = Join(RemArrDups, ", ")
    
        End With
    Next

End Sub

与连接相关的行给出了运行时错误5 "无效的过程调用或参数"。这是为什么？
如果我在arrMatchID而不是RemArrDups上使用Join函数，它会起作用，但这样的话，值就不会是唯一的。