@acperkins how right you are - cheers :) in the case I would use something like
select CC.Email, C.id
from Contact CC, Customer C
where C.id = CC.Customer
and not exists -- test the a more recent record doesn't exist
(
select 1
from Contact CC1, Customer C1
where C1.id = CC1.Customer
and CC1.id <> C.id
and C1.Save_Time > C.Save_Time
)