[... regarding compounding subject prefixes in cross-posted maillist messages, and more generally avoiding duplication of cross posts ...]
On Fri, 29 Jan 1999, Christian Tismer wrote:
It seems to be hard to tackle this in a more intelligent way. Ok, we can prevent prefixes from stacking. But the bigger problem which hurts at the same time (See Chris Petrilli's message) is that you get these crossposted things twice, also.
I don't see an easy way to avoid this when cross posting is allowed. One way would be this:
Offhand, there seem to me to be two key items here:
mailman can unequivocally identify the message id and the recipients of members of any lists which it is serving on the same host, so given a decent architecture (modularized message flow tracking db) it should be easy to provide users the option to inhibit receiving more than the first copy of a cross posted message
this issue does not seem critical enough to retrofit it to the existing architecture (which does virtually no flow tracking, certainly not across lists), at least not compared to the various rough edges that currently need to be polished off (eg, subscription delivery address changing without un/resubscribe, better implementation of admin pending items, lots of other stuff.)
When Mailman receives a post, it can see all the recipients, especially it can see its own hostname, with different mailing lists. Unfortunately, the receiving process will duplicate the message and send it to the different aliases, one for each list. To capture this, sendmail must be intercepted by something like procmail (just as an example) which first makes sure that only one list gets that message.
Um, it doesn't make sense to go external when all the info is available internally to mailman as a whole! Instead, the internal infrastructure needs to be developed - something that should go on the list for modular mailman, or whatever it'll be...
Ken