[exim] Greylisting, and expansion?

I am having a bit of problem with greylisting (greylistd
0.8.3 in Debian).

I am using the below ACL, but yet the /24-bit does not work. If you look at
the bottom, you see an example.

I have 301 seconds in /etc/greylist/config (also included) but every IP is
treated as a "new" entry, even if they are in the same /24 netmask.

Where am I going wrong?

acl_check_rcpt:

# Accept if the source is local SMTP (i.e. not over TCP/IP). We do this by
# testing for an empty sending host field.

accept hosts = :
accept authenticated = *

defer
                message = Please try later.
                !hosts      = /etc/greylistd/whitelist-hosts
                !senders    = :
#               !acl        = acl_clean_helo
                log_message = greylisted.
                set acl_m9  = ${mask:$sender_host_address/24}
$sender_address $local_part@$domain
                set acl_m9  =
${readsocket{/var/run/greylistd/socket}{$acl_m9}{5s}{}{}}
                condition   = ${if eq {$acl_m9}{grey}{true}{false}}

May 4 22:56:50 scooter exim: 2006-05-04 22:56:50
H=bay18-f20.bay18.hotmail.com (hotmail.com) [65.54.187.70]
F=<heidi-e113421@???> temporarily rejected RCPT
<battine@???>: greylisted.
May 4 22:56:50 scooter exim: 2006-05-04 22:56:50
H=bay18-f20.bay18.hotmail.com (hotmail.com) [65.54.187.70]
F=<heidi-e113421@???> temporarily rejected RCPT
<battine@???>: greylisted.
May 4 22:57:54 scooter exim: 2006-05-04 22:57:54
H=bay18-f20.bay18.hotmail.com (hotmail.com) [65.54.187.70]
F=<heidi-e113421@???> temporarily rejected RCPT
<battine@???>: greylisted.
May 4 22:57:54 scooter exim: 2006-05-04 22:57:54
H=bay18-f20.bay18.hotmail.com (hotmail.com) [65.54.187.70]
F=<heidi-e113421@???> temporarily rejected RCPT
<battine@???>: greylisted.
May 4 22:58:57 scooter exim: 2006-05-04 22:58:57
H=bay18-f20.bay18.hotmail.com (hotmail.com) [65.54.187.70]
F=<heidi-e113421@???> temporarily rejected RCPT
<battine@???>: greylisted.
May 4 22:58:57 scooter exim: 2006-05-04 22:58:57
H=bay18-f20.bay18.hotmail.com (hotmail.com) [65.54.187.70]
F=<heidi-e113421@???> temporarily rejected RCPT
<battine@???>: greylisted.
May 4 23:04:07 scooter exim: 2006-05-04 23:04:07
H=bay18-f5.bay18.hotmail.com (hotmail.com) [65.54.187.55]
F=<heidi-e113421@???> temporarily rejected RCPT <battine@???>:
greylisted.
May 4 23:04:07 scooter exim: 2006-05-04 23:04:07
H=bay18-f5.bay18.hotmail.com (hotmail.com) [65.54.187.55]
F=<heidi-e113421@???> temporarily rejected RCPT <battine@???>:
greylisted.
May 4 23:05:10 scooter exim: 2006-05-04 23:05:10
H=bay18-f5.bay18.hotmail.com (hotmail.com) [65.54.187.55]
F=<heidi-e113421@???> temporarily rejected RCPT <battine@???>:
greylisted.
May 4 23:05:10 scooter exim: 2006-05-04 23:05:10
H=bay18-f5.bay18.hotmail.com (hotmail.com) [65.54.187.55]
F=<heidi-e113421@???> temporarily rejected RCPT <battine@???>:
greylisted.
May 4 23:06:13 scooter exim: 2006-05-04 23:06:13
H=bay18-f5.bay18.hotmail.com (hotmail.com) [65.54.187.55]
F=<heidi-e113421@???> temporarily rejected RCPT <battine@???>:
greylisted.
May 4 23:06:13 scooter exim: 2006-05-04 23:06:13
H=bay18-f5.bay18.hotmail.com (hotmail.com) [65.54.187.55]
F=<heidi-e113421@???> temporarily rejected RCPT <battine@???>:
greylisted.

[timeouts]
retryMin     = 301
retryMax     = 28800
expire       = 5184000

[socket]
path         = /var/run/greylistd/socket
mode         = 0660

[data]
update       = 600
statefile    = /var/lib/greylistd/states
tripletfile  = /var/lib/greylistd/triplets
savetriplets = true