Why doesnt this sort my resultset on the subject column?
For the sortExpression parameter I tried filling in 'title', 'e.title', 'e.title asc', but none of them seem to work!

create PROCEDURE [dbo].[_getCompanyEmailsByIdSorted]
     @startRowIndex int
    ,@maximumRows int
    ,@companyID int
    ,@sortExpression nvarchar(20)

AS
BEGIN
    SET NOCOUNT ON;
--set the default sortfield
if @sortExpression=''
set @sortExpression='e.title'

SELECT *
FROM

(select ROW_NUMBER() OVER (ORDER BY @sortExpression) as RowNum,e.*
FROM emails e
INNER JOIN campaigns camp ON camp.uuid = e.campaignUUID
INNER JOIN companies c ON c.id = camp.companyID
WHERE camp.companyID = @companyid

) as Info

WHERE RowNum > @startRowIndex AND RowNum <= (@startRowIndex + @maximumRows)

END



DECLARE @RC int
DECLARE @startRowIndex int
DECLARE @maximumRows int
DECLARE @companyID int
DECLARE @sortExpression nvarchar(20)

   set @startRowIndex=0
  set @maximumRows=100
  set @companyID=2
  set @sortExpression='subject'

EXECUTE @RC = [mycampaign].[dbo].[_getCompanyEmailsByIdSorted]
   @startRowIndex
  ,@maximumRows
  ,@companyID
  ,@sortExpression