"Erik Howard" <[EMAIL PROTECTED]> wrote:
>I've been running Qmail now for a couple of years without incident and
>without any real problems. But I was wondering what makes Qmail faster than
>most mailers. Can someone enlighten me on the various reasons. Thanks in
>advance.
That's a good question.
Basically, qmail is fast because it was designed to be fast and
because the code was written by a talented programmer.
Specifically, qmail blasts mail out quickly because:
1) Each recipient of a message gets its own qmail-remote, so
qmail-rspawn doesn't have to spend lots of time looking up MX's,
sorting, combining, etc.
2) Up to concurrencyremote qmail-remotes run simultaneously, unlike
Sendmail which delivers to one recipient at a time.
3) All of the qmail processes are small, so they use up less memory,
resulting in less swapping and paging.
4) qmail's queue is split into multiple directories to minimize the
penalty of linear directory searches.
For incoming mail, qmail is less dramatically faster than other MTA's
because there's less room for improvement. Of course, the small
processes and queue splitting help.
qmail 2.0 promises to raise the bar with its "zeroseek" queue. See
ftp://koobera.math.uic.edu/www/qmail/future.html
for more information.
-Dave
