[exim] condition = lookup not working

Hi folks,

I'm still looking at setting up rate limiting on my servers. The basic setup I
put in before Christmas had made a great difference to the hammering my
servers are getting but it is blocking some genuine emails too.

Therefore I'm trying to set up an exclude list, including trusted servers.
I've got the following code:

   warn 
# GPS added 2013-12-31
# rate limit anything except: local LAN, hosts in /etc/exim/no_rate_limit
        hosts      = !+internal_lan
       condition  = ${if ${lookup{$sender_helo_name} \ 
               partial-lsearch{/etc/exim/no_rate_limit}} {no}{yes} } 
        ratelimit = 100 / 5m / strict
        log_message = RATE UPDATE: $sender_rate/$sender_rate_period \
                (max $sender_rate_limit)

However, I then get the following error.

2013-12-31 11:08:06 H=mta20134.pur3.net [94.236.20.134] temporarily rejected
MAIL <agent@???>: failed to expand ACL string "${if
${lookup{$sender_helo_name} partial-lsearch{/etc/exim/no_rate_limit}} {no}
{yes} }": condition name expected, but found "${lookup{$sender"

Ta
Gary
--
Gary Stainburn
Group I.T. Manager
Ringways Garages
http://www.ringways.co.uk