[Pkg-exim4-users] Can't accept IP range for relay hosts

[Rob Feldman]

In update-exim4.conf.conf, the entry:
  dc_relay_nets='192.168.254.103'
works fine. Sending message from workstation with that IP results in:
  2009-12-11 16:15:10 1NJCpS-0000FR-Iw <= trailriders at wherever.com
H=(RCTRConcession) [192.168.254.103] P=smtp S=824
id=4465AB9F44964717906A4F8B553545F7 at RCTRConcession
  
Change update-exim4.conf.conf to:
  dc_relay_nets='192.168.254.101/200'
results in failure:
   2009-12-11 16:01:35 H=(RCTRConcession) [192.168.254.103]
F=<trailriders at wherever.com> rejected RCPT <rob at wherever.com>: relay not
permitted
  
How on earth is xxx.xxx.xxx.103 not in the range xxx.xxx.xxx.101/200? Where
do I go from here to get exim4 to relay from all my DHCP hosts?