[Exim] Adding an ACL Entry

Hi.

I have Exim 4.2 and NetBSD 1.6. I am trying to setup pop Before SMTP on
my server and it tells me to add an ACL entry liek this below:

require condition = \
     ${lookup whoson {$sender_host_address}{yes}{no}}

What is the correct syntax for adding this? I have tried a few things but
nothing seems to work.

Thanks
Frank

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Frank DeChellis
Internet Access Worldwide
3 East Main Street    Welland, Ontario, Canada    L3B 3W4
905-714-1400     fax 905-732-0524
www.iaw.com
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