Thanks for your quick response. However, that did not work for me. I am using Microsoft SQL server Management Studio.
I also tried....which is still returning too many records.
select a.id, A.PERSON_MULTIPLE_SOURCES
from dbo.ODS_PERSON_SOURCES A
FROM dbo.ODS_PERSON_MAIL_RULES B
WHERE ((MAIL_RULES != 'XNC' OR MAIL_RULES IS NULL)))
and PERSON_MULTIPLE_SOURCES IN ('ADA','AEA')