[Exim] Ip_blocked syntax

this is located in the configure file.

hostlist = blocked_ip = /usr/exim/filter/blocked_ip

Will this work. I am attempting to block certain ranges of IP addresses.

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In the blocked_ip file they are listed similar to this

210.0.0.0/8
211.1.1.0/24
212.2..0.0/16

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Will this work?? Is the syntax correct??

Thanks