Dynamic Order By W/ Additional Parameters

I have a stored procedure that uses a dynamic order by statement.  This statement works okay until I try to select ticket's by userEmail which is passed in to my stored procedure as a parameter.  Here is the code that works for my dynamic sort order:

CREATE PROCEDURE [dbo].[SelectAllTickets]

@SortOrder varchar(250)

AS

SET NOCOUNT ON

Exec('SELECT a.TicketID, a.TicketDate, a.TicketName, a.TicketDescription, a.statusID, a.resolutionID, a.userID,

b.typeID, b.typeName,

c.userID, c.UserFirstName,

f.statusID, f.statusName

FROM Tickets a

LEFT OUTER JOIN Type b ON b.typeID = a.typeID

LEFT OUTER JOIN Users c ON c.userID = a.userID

LEFT OUTER JOIN Status f ON f.statusID = a.statusID

ORDER BY ' + @SortOrder)

I modied this procedure to create one in which I select tickets based on the userEmail as a criteria as well.. this one fails due to Incorrect syntax near the keyword 'BY'

CREATE PROCEDURE [dbo].[SelectTicketByUser]
@SortOrder varchar(250),
@userEmail varchar(50)

AS
   SET NOCOUNT ON
   Exec('SELECT a.TicketID, a.TicketDate, a.TicketName, a.TicketDescription, a.statusID, a.resolutionID, a.userID,
  b.typeID, b.typeName,
  c.userID, c.UserFirstName, c.userEmail,
  f.statusID, f.statusName
      FROM Tickets a
 LEFT OUTER JOIN Type b ON b.typeID = a.typeID
 LEFT OUTER JOIN Users c ON c.userID = a.userID
 LEFT OUTER JOIN Status f ON f.statusID = a.statusID
 WHERE a.statusID <> 40 AND c.userEmail = ' + @userEmail +
 'ORDER BY ' + @SortOrder)

Any ideas on what syntax I should be using? Thanks!