[Mailman-Users] sending messages

J C Lawrence claw at kanga.nu
Fri Dec 3 19:20:03 CET 1999

On Fri, 03 Dec 1999 11:03:31 -0700 
Kory Wheatley <wheakory at isu.edu> wrote:

> Can mailman be configured to send e-mails in small batches with
> several minute pauses in between? When it tries to send hundreds
> (or even thousands) of messages as quickly as it can, it can cause
> problems.

I'm not sure what problem you are trying to resolve here (I may have
been over zealous with the delete key earlier in the thread), but I
suspect that the real problem is not what you think it is.

The easiest way to control such things is at the MTA level.  Good
MTAs can have a variety of limits set:

  Max number of inbound connections
  Max number of messages received on a connection.
  System load at which to stop trying to send messages and queue only instead
  Max system load to accept messages at


Fiddle with these, as appropriate to your MTA, and you should be
able to get what you're asking for,

Note: Sendmail is pathologically bad at handling large spools.  This
is actually the main reason it is not used at large mail sites (bad
security they think they can live with, bad performance they can't
even contemplate).  Postfix, Exim, QMail and even SMail are
significantly more efficient at emptying large spools quickly with
minimum fuss than Sendmail.  Example:

  Given a bunch of messages all addressed to bubba at redneck.com which
  arrived at various times over the last couple hours and which are
  sitting in your spool:

    Sendmail will work thru the spool in order, and upon
    encountering one of these messages, will attempt to deliver it,
    and will then move on to the next message in order in the spool
    no matter if they successfully delivered the message.  This is

    More intelligent MTAs will work thru the spool, encounter a
    bubba at redneck.com message, attempt to deliver it, and if
    successfull will then immediately try and deliver every other
    messaage they have waiting for redneck.com, often forking other
    queue runners to attempt multiple deliveries in parallel to
    redneck.com to get the queue emptied as fast as possible.  

J C Lawrence                                 Home: claw at kanga.nu
----------(*)                              Other: coder at kanga.nu
--=| A man is as sane as he is dangerous to his environment |=--

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