Email not received from database even rows available as below query.. could suggestion me, what could be worng as below coding..I want receive email when rows available if no rows selected don't want send mail..

if EXISTS (Select A.MACHINE, A.Instance, B.InstanceA,

(B.InstanceA-A.Instance) as Diff from (select MACHINE, COUNT(*)

as Instance from PROD.dbo.CM_INSTANCE group by MACHINE) A,

(Select COUNT(*)/4 as InstanceA from PROD.dbo.CM_INSTANCE) B

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

begin

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

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

@subject='Alert!-Verify Instance',

@query= 'Select A.MACHINE, A.Instance, B.InstanceA,

(B.InstanceA-A.Instance) as Diff from (select MACHINE, COUNT(*)

as Instance from PROD.dbo.CM_INSTANCE group by MACHINE) A,

(Select COUNT(*)/4 as InstanceA from PROD.dbo.CM_INSTANCE) B

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

end