[exim] dkim body has been altered

I have in my config

DKIM_DOMAIN = ${lc:${domain:$h_from:}}
DKIM_FILE = /usr/local/etc/exim/dkim/${lc:${domain:$h_from:}}.priv
DKIM_PRIVATE_KEY = ${if exists{DKIM_FILE}{DKIM_FILE}{0}}

remote_smtp:
driver = smtp
dkim_selector = dkim
dkim_domain = DKIM_DOMAIN
dkim_private_key = DKIM_PRIVATE_KEY
dkim_strict = 0
dkim_canon = relaxed

But when I run the test here it fails with a body has been altered
http://www.brandonchecketts.com/emailtest.php

------------

Message contains this DKIM Signature:
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
    d=bluelight.org.uk; s=dkim; h=Message-ID:Date:From:MIME-Version:
    To:Subject:Content-Type:Content-Transfer-Encoding; bh=frcCV1k9oG
    9oKj3dpUqdJg1PxRT2RSN/XKdLCPjaYaY=; b=dhX+v12SRv1g8cg4buojCvaWVS
    MqhNLi2afZiAx5EyRYcHOUU5eiNyvkLt6689O/+2mPMLQkmHtGA4UTdCCPHjJ

Signature Information:
v= Version:         1
a= Algorithm:       rsa-sha256
c= Method:          relaxed/relaxed
d= Domain:          bluelight.org.uk
s= Selector:        dkim
q= Protocol:        
bh=                 frcCV1k9oG
    9oKj3dpUqdJg1PxRT2RSN/XKdLCPjaYaY=
h= Signed Headers:  Message-ID:Date:From:MIME-Version:
    To:Subject:Content-Type:Content-Transfer-Encoding
b= Data:            dhX+v12SRv1g8cg4buojCvaWVS
    MqhNLiisnk3F6eYJx06AZ2I2i4zGdjGpGNqVFUmoS2afZiAx5EyRYcHOUU5eiNyv
    olkVGbkLt6689O/+2mPMLQkmHtGA4UTdCCPHjJ

    Public Key DNS Lookup

Building DNS Query for *dkim._domainkey.bluelight.org.uk*
Retrieved this publickey from DNS: v=DKIM1; p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhAL6sgj6uA/v/UPVxVBluitTsKEd3xKcDwrey0YoUIDlmp/AbOoXvt7c8ip1sOQlY2BqfR+Sow47+zSVAf0IAoMTI41ybtj/2mAq2AtElWCp6qIR1llgY0Xk+c6ifpXxuwwIDAQAB

    Validating Signature

result = fail
Details: body has been altered
-------------------

Another site says it passes fine

exim version 4.69