-- FROM admin@system.org
SELECT
--admin
LEFT(emailAddres, CHARINDEX('@', emailAddres) - 1) AS accountName
--system.org
RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres)) AS domainWithExtension
--system
LEFT(RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres)), CHARINDEX('.', RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres))) - 1) AS domain
--org
RIGHT(RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres)), LEN(RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres))) - CHARINDEX('.', RIGHT(emailAddres, LEN(emailAddres) - CHARINDEX('@', emailAddres)))) AS extension