I have HUGE loads from exim, and my stats are below. I'm looking for a tutorial on how to secure my exim. I'm on a cpanel server with WHM. Please advise!

Top 50 sending hosts by message count
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35078 147MB local
1505 7716KB (postino13.prima.com.ar)
829 5051KB (barroco.com.br)
321 2521KB (mail.amazon.com.br)
182 1268KB (mx.uol.com.br)
138 794KB (tarpals.ns1.com.br)
44 227KB (cumeils.prima.com.ar)
37 185KB (mxdc01.bomjesus.br)
36 105KB (apus.netpar.com.br)
30 53KB (140998968)
27 48KB (earthlink.net)
27 47KB (145475136)
25 171KB (mx.bol.com.br)
22 60KB (baydenet.com.br)
21 124KB (mercury.antares.com.br)
20 92KB (acsle0.ambev.com.br)
18 77KB (acsle1.ambev.com.br)
18 31KB (143841488)
16 106KB (mailer.ulbra.br)
15 26KB (145408576)
14 102KB (mxfilter2.servepath.com)
14 79KB (oberon.sc.senac.br)
14 73KB (moscou.bluenet.com.br)
14 49KB (friend)
14 25KB (145640528)
14 24KB (143456128)
13 73KB (unikey.com.br)
12 88KB (localhost)