[exim] Hotmail sends spam multiple times

Hello,

I am wondering if any of you has got this kind of behavior from hotmail
servers, and if yes, how do you deal with this?
When I receive some spams from hotmail, it is fake-rejected following
recommendations of spamassassin ACL in DATA phase. But hotmail keeps
re-sending the same spam again multiple (20-30) times. According to the
spam headers, this is the same message, not another one being submitted.
This is quite annoying as spamassassin takes ressources scanning the
same spam over and over again and the user receives the spam multiple
times in the spam folder.
Here is an example:
009-02-02 20:21:26 [5420] 1LU4LI-0001PQ-Dl <= ckf_37@???
H=bay0-omc1-s27.bay0.hotmail.com [65.54.246.99]:47498
I=[206.251.244.96]:25 P=esmtp S=7686
id=BAY124-W5932A813ABDFF94458F3BDF0C50@??? T="I am waiting for your
urgent reply." from <ckf_37@???> for renaud@???
2009-02-02 20:24:33 [13632] 1LU4OJ-0003Xs-PB <= ckf_37@???
H=bay0-omc1-s27.bay0.hotmail.com [65.54.246.99]:58221
I=[206.251.244.94]:25 P=esmtp S=7686
id=BAY124-W5932A813ABDFF94458F3BDF0C50@??? T="I am waiting for your
urgent reply." from <ckf_37@???> for renaud@???

Best Regards