Re: [cobalt-users] [Raq2] e-mail duplication

[Mailing List Account <listmail@xxxxxxxxxxx>]

On Sat, 5 Apr 2003, Chris "Oger" Gebhardt wrote:

> Thanks guys... I have checked the logs and I cannot see that there were any
> interruptions during download.  The only message filter on the client side
> is to leave a copy of the message on the server (don't delete) - but that is
> only in some cases.  This problem happens intermittently to just about all
> users.
>
> The messages can be to multiple recipients, or just one recipient.
>
> Very strange.  Not life-ending, but strange.

	Not all that strange. If sendmail dies halfway through a send of
multiple messages the recipients of that message will receive multiple
copies of the messages. The definition of die does enter into the
equation. If the queue, for example, fills up (uses all available drive
space) sendmail won't drop dead but it will choke and puke and cough a
lot and the recipients of a message that was being sent when the queue
filled will receive duplicate copies of the message. Based upon our
experience here this kind of thing most often happens when a list is
mailed but all messages being sent at that time will be affected. The only
way you can eliminate the problem is by increasing the queue size or
lowering the load on the server. Sendmail, however, does provide an option
to limit the number of people that receive duplicate copies:

	define(`confCHECKPOINT_INTERVAL',`4')

	4, as used in the example above, is the value recommended in the
Bat Book. It's also the value we run on our list servers here and we
haven't had a lick of a problem since we started doing it. We learned
about this the hard way - a 15,000 member list was mailed for the first
time on our servers, the queue got stuffed and before we figured out what
the heck was happening each and every member of that 15,000 member mailing
list received some 10 copies of the mailing ...the resulting complaint
calls prompted us to learn a bit about sendmail.

	You'd add the above your sendmail.mc file and compile a new
sendmail.cf file. Beleave it or not I've never even looked inside of a
sendmail.cf file but I suspect that the option may be included in the
basic config file but commented out. So you might be able to find it and
uncomment it and set it directly in the config file if you don't want to
deal with working from the sendmail.mc file (the easy way :-)

	Best Regards,

	Brent