[exim] Relaying for IP address range

Hi All,

I'm having problems setting up a relay for an external IP address range,
the following has been setup in acl_check_rcpt

accept
    hosts = SPECIAL_RELAY
    log_message = "SPECIAL ACCEPT: $sender_address locally specially whitelisted"

SPECIAL_RELAY is defined in listmacrodefs as 213.185.*.*

When I test with exim -bh I get the 'relay not permitted' message.

Should it be defined as 213.185.0.0/16?

Am I doing this completely wrong or is there something small missing?
Any help greatly appreciated.

exim4-daemon-heavy 4.62-4

Thanks,
Mark