On Tue, 21 Apr 2015, Wilfred van Velzen wrote to Bj”rn Felten:

 WvV> However good dupe detecting is important to prevent unnecassary 
 WvV> dupes like the Path example I gave before, where a message passes 
 WvV> through a system for the second time without being detected as 
 WvV> dupe. That's just plain stupid... 

it seems to me that CPD (Circular Path Detection) is another/additional dupe
detection method/feature and that not all mail tossers offer it... some might
say that things should just work without CPD but the fact remains that the
checksums and such of the messages processed need to be stored somewhere...
those databases may be one database for all message areas carried by a system
(counting or not being done for passthru areas!) or they may be separate
databases for each area... synchronet uses separate databases and allows the
operator to set the number of checksums stored in each...

perhaps, instead of calling it "stupid", one might suggest to those tosser
authors and maintainers that they add it to their tossers? perhaps someone
might even read the code to see if sbbsecho does, in fact, not perform dupe
checking on mail being sent to links? perhaps someone might even provide the
code to fix this if it is not already being done and they might additionally
provide code for CPD if it is not already included ;) ;) ;) 

)\/(ark