Excel: Find unique values in column

Excel: Find unique values in column

Sub FindUniqueValues()
    Call Rows("1:1").Insert(Shift:=xlDown)
    Range("A1").Value = "Email"
    Range("B1").Value = "Unique"
    Call Columns("A:B").Sort(Key1:=Range("A2"), _
        Order1:=xlAscending, Header:=xlYes, _
        OrderCustom:=1, MatchCase:=False, _
        Orientation:=xlTopToBottom, _
        DataOption1:=xlSortNormal)
        
    Dim wks As Worksheet
    Set wks = ThisWorkbook.ActiveSheet
    Dim startCell As Range, endCell As Range:
    Set startCell = Range("B2")
    Set endCell = wks.Cells.SpecialCells(xlCellTypeLastCell)
    startCell.FormulaR1C1 = "=RC[-1]<>R[1]C[-1]"
    Dim r As Range
    Set r = Range(startCell, endCell)
    Call startCell.AutoFill(Destination:=r)
    Call wks.Calculate
    Set r = Columns("A:B")
    Call r.AutoFilter
    Call r.AutoFilter(Field:=2, Criteria1:="TRUE")
End Sub