On Fri, 4 Jun 1999, Vadim Vygonets wrote:
> Why? Diapup is just a host wrich needs to receive no connections
> (except from localhost, if people on this machine use MH), which
> sometimes wants to re-write all the outgoing addresses, and
> usually sends all the outgoing mail to a smarthost.
Dial-up hosts need *not* to try to deliver remote deliveries
immediately, but when they do, they should do the entire queue down the
same SMTP connection. Exim is not optimized for handling large queues -
it was designed for online hosts that can deliver mail immediately most
of the time, so the queuing apparatus is simple because it is designed
for handling only exceptions. (The two hosts forming this system handle
around 20,000 messages per day each, but the queues are rarely above
40 messages long.)
Of course it can be done in Exim, but it is not tidy. You have to use
-queue_remote and -qqf. The second one does two scans of the queue,
doing all the (identical) routing for each address, saving message ids
in a file, and then the second scan picks these all up. It is a pile of
over-heavy apparatus and if the queue is of any length, the resource
wastage might be significant. I certainly would have built something
different if I had had dial-up in mind.
On the other end of the wire, if Exim is used as a server for dial-in
hosts there are different infelicities to deal with.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
--
*** Exim information can be found at
http://www.exim.org/ ***
