Thanks for reply.. I have changed the script for email notification as below and sending email number of records not to be zero

select MACHINE, COUNT(*) as Instance

into #tableA

from PROD.dbo.CM_INSTANCE

group by MACHINE

Select COUNT(*)/4 as InstanceA

into #tableB

from PROD.dbo.CM_INSTANCE

Select A.MACHINE, A.Instance, B.InstanceA,

(B.InstanceA-A.Instance) as Diff

into #results

from #tableA A,

#tableB B

where (B.InstanceA-A.Instance) < -3 or (B.InstanceA-A.Instance) > 3

-- If you are wanting the number of records to not be zero

If ((select count(*) from #results) <> 0)

Begin

EXEC msdb.dbo.sp_send_dbmail @profile_name='db_mail',

@recipients='ananad.murugesan@ril.com',

@subject='Alert!-Verify Instance',

@query='select * from #results'

End

drop table #tableA

drop table #tableB

drop table #results