[exim] Trying to block all WAN sent zip emails

Hi all

Im trying to get it that I block all zip files, but users in my LAN can
send zip files. Ive tried the following, but yet if I send from my gmail
account, the zip file gets accepted.

deny message = This message contains a prohibited file extension 
(${extract{-1}{.}{${lc:$mime_filename}}})
hosts = !+relay_from_hosts :
#!hosts = 192.168.111.0/24
log_message = BAD_ATTACHMENT (${extract{-1}{.}{${lc:$mime_filename}}})
condition = ${if match{${extract{-1}{.}{${lc:$mime_filename}}}}{\N^( \
                       zip\
                       )$\N}{1}{0}}

If someone could assist, it would be appreciated.

Kind Regards
Brent Clark