As noted, use NOT EXISTS.  Also, uniquely cluster the NoEmail table on the EmailAddress.


...
CREATE TABLE #tblNoEmail
(
EmailAddress varchar(100) PRIMARY KEY CLUSTERED
)
...
SELECT *
FROM #tblContacts C
INNER JOIN #tblEmails E ON C.ContactID = E.ContactID
WHERE NOT EXISTS (
    SELECT 1
    FROM #tblNoEmail NE
    WHERE E.EmailAddress = NE.EmailAddress
)