[ Kelly Feagans writes: ]
> I have a few lists that are quite large, both have over 2500 subscribers.
> I have been receiving complaints that subscribers are receiving multiple
> mailings of the same message (that is only sent once). Interesting, since
> this does not happen with my smaller lists. I am thinking there is a
> problem between sendmail and Majordomo, but I dont know.
Unless *all* the subscribers are receiving duplicates, this is a symptom
of your sendmail queue scan interval being too short such that delivery
is still in progress (probably due to difficulties delivering to some
addresses) when another queue scan is initiated. You might want to
investigate other delivery agents such as bulkmail or Jason's 3-letter
bulk mailer (I forget what he calls it at the moment, but I'm sure he'll
provide you with details).
If everyone is getting duplicates, then one of your subscribers has a
screwed up MTA or mail system that is echoing received mail back to the
list. Check the Received headers on the duplicates (you may need to
change the list configuration to not strip Received headers) to get an
idea of who the culprit is.