[exim] Exim4 + greylistd + spf

Hi!

A few months ago I installed Ex Exim 4.5-8 + Clamav + Greylist on
my Debian Sarge. When i started to get spams coming through the greylist
I decided to install SPF as first filter. Unfortunately, I am since then
receiving more spams than ever instead of none at all as intended by
SPF. Could you please help me?

Here is my configuration in the exim4.conf.template file:

acl_check_rcpt :

defer
    message        = $sender_host_address is not yet authorized to deliver \
                     mail from <$sender_address> to <$local_part@$domain>. \
                     Please try later.
    log_message    = greylisted.
    !senders       = :
    !hosts         = : +relay_from_hosts : \
                     ${if exists {/etc/greylistd/whitelist-hosts}\
                                 {/etc/greylistd/whitelist-hosts}{}} : \
                     ${if exists {/var/lib/greylistd/whitelist-hosts}\
                                 {/var/lib/greylistd/whitelist-hosts}{}}
    !authenticated = *
    !acl           = acl_whitelist_local_deny
    domains        = +local_domains : +relay_to_domains
    verify         = recipient/callout=20s,use_sender,defer_ok
    set acl_m9 = -ipv4=$sender_host_address \
                                 -sender=$sender_address \
                                 -helo=$sender_helo_name
    set acl_m9 = ${run{/usr/bin/spfquery $acl_m9}}
   condition      = ${${if eq 
{$runrc}{1}{readsocket{/var/run/greylistd/socket}\
                                 {--grey \
                                  $sender_host_address \
                                  $sender_address \
                                  $local_part@$domain}\
                                 {5s}{}{false}}}{false}}

These are the instructions I followed to install SPF:
http://slett.net/spam-filtering-for-mx/exim-spf.html#exim-spf-exiscan

I checked through the mailing list archives and on google but I did not
find anything.

Thanks in advance!