Re: Qmail/Postfix/Sendmail for fastest outgoing mail
I remember, that sendmail, exim, and others have queuing strategies,
that try to minimize the number of remote conections.
El lun, 25-11-2002 a las 07:00, Craig Sanders escribió:
> On Mon, Nov 25, 2002 at 11:37:58PM +1100, Jason Lim wrote:
> > > nope, because postfix has no way of knowing that they were
> > > originally the same email(*). postfix has been handed 10 individual
> > > emails by qmail, so it will deliver 10 individual emails.
> >
> > Mmm... but, for example, if it scanned it's queue every 30 seconds,
> > for example, it could then combine them together?
>
> nope.
For example at www.exim.org you find the following paragraphs:
SMTP batching
When an SMTP delivery attempt fails, causing the message to be
deferred till later, Exim updates a DBM database that contains
records
keyed by host name plus IP address. Each record holds a list of
messages that are waiting for that host and address.
When an SMTP delivery succeeds, Exim consults the database to see if
there are any other messages waiting for the same host and address.
If
it finds any, it creates a new Exim process and passes it the open
SMTP channel and a message identification. The new process then
delivers the waiting message down the existing channel and may in
turn
cause the creation of yet another process. Any other waiting
addresses
in the message are skipped. The maximum number of messages sent down
one connection is configurable.
This scheme achieves some SMTP efficiency when a number of messages
have been queued up for a given host, without the overhead of a
heavyweight queueing apparatus.
---
This is similar to what I'm talking about. I'm just looking to increase
efficiency with sending millions of emails.
> > Nope... not running ezmlm at all, just a lot of CGIs (through
> > web/Apache) sending emails. Actually... I wonder... is there any
> > drop-in replacement for /usr/sbin/sendmail that would just dump the
> > emails to another server for actual sending? This should not affect
> > receiving email in the least (hence minimize disruption) but would
> > need to be able to dump the emails at a high rate. I'm not sure if
> > there is such a thing though.
In your scenario you could forward the messages to the mail-sending box
via the QMTP protocol provided by Qmail. On the Mail sending box you
just receive via QMTP and hand it over to Postfix or whatever you decide
to use for outgoing mail.
QMTP is loooooots faster then SMTP.
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But only Qmail supports QMTP, which means the outgoing server must be
running QMTP too?
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