[exim] Mail claims to be sent by my self

Hi over the last 2 weeks I am suddenly getting a lot of spam that claims
I sent it which of course i didnt.
What sort of acl could I use to catch it ?

Here is what shows in my logs

---------
2008-12-21 17:39:36 1LESH5-0009Zl-3u <= terry@???
H=host81-153-121-27.range81-153.btcentralplus.com [81.153.121.27]:2656
I=[217.112.92.232]:25 P=smtp S=3067 T="Your sales agent for consumer
healthcare products" from <terry@???> for terry@???
2008-12-21 17:39:38 1LESH5-0009Zl-3u => terry@???
<terry@???> F=<terry@???> P=<terry@???>
R=dnslookup T=remote_smtp S=3128 H=mail.bluelight.org.uk
[80.229.144.50]:25 C="250 OK id=1LESHQ-00019y-Si" QT=7s DT=1s
2008-12-21 17:39:38 1LESH5-0009Zl-3u Completed QT=7s

Thanks