SELECT 
accountno,address2
,cs.contsupref+address1 AS 'E-Mail Address' 
FROM 
contsupp cs
WHERE 
(cs.CONTACT = 'E-mail Address') 
AND (SELECT 
CASE 
WHEN cs.contsupref IS NULL 
OR CHARINDEX('@.',cs.contsupref+address1) > 0 
OR CHARINDEX('.@',cs.contsupref+address1) > 0 
OR CHARINDEX('..',cs.contsupref+address1) > 0 
OR CHARINDEX('"', cs.contsupref+address1) <> 0 
OR CHARINDEX('(', cs.contsupref+address1) <> 0 
OR CHARINDEX(')', cs.contsupref+address1) <> 0 
OR CHARINDEX(',', cs.contsupref+address1) <> 0 
OR CHARINDEX('<', cs.contsupref+address1) <> 0 OR CHARINDEX('>', cs.contsupref+address1) <> 0 
OR CHARINDEX(';', cs.contsupref+address1) <> 0 
OR CHARINDEX(':', cs.contsupref+address1) <> 0 
OR CHARINDEX('[', cs.contsupref+address1) <> 0 
OR CHARINDEX(']', cs.contsupref+address1) <> 0 
OR RIGHT(RTRIM(cs.contsupref+address1),1) = '.'
OR CHARINDEX(' ',LTRIM(RTRIM(cs.contsupref+address1))) > 0 
OR LEN(cs.contsupref+address1)-1 <= CHARINDEX('.', cs.contsupref+address1) 
OR cs.contsupref+address1 LIKE '%@%@%' 
OR cs.contsupref+address1 NOT LIKE '%@%.%' THEN 0 
ELSE 1 
END) = 0