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Re: qmail or postfix? (was: RE: What is the best mailling list manager for qmail and Domain Tech. Control ?)



Bjørnar Bjørgum Larsen wrote:

I am in the process of choosing between postfix and qmail for our
mail relays. I've not decided yet. However, I am surprised by the
fact that many people who prefer postfix, also enjoy posting
unqualified[0] statements[1][2][3] about qmail.

If anyone have properly grounded views, please share!

<rant>
Qmail does _everything_ like DJB thinks is the right way:
- The FHS doesn't exist
- /sbin/init and inetd suck, because they're based on 30 year old design
- ....
</rant>

The biggest problem with qmail is it's license, as it permits to release a secure _and_ feature-rich binary distribution. This may be no big reason for one or two people managing one or two servers, but in an ISP environment I (and many other) prefer to save time by using "apt-get install".

Another problem is: qmail (at least in standard configuration) is an I/O hog. At one client it was unable to saturate a T1 from a celeron 433 machine with a cheap IDE drive. Postfix in standard configuration outperformed it by factor 5 (and maybe more, since the T1 was saturated then).

I was pretty confused about the number of config files. Yes, even Postfix has some, but there's not one config file for each subsystem. (That argument applies to Sam Varchawik's software [Courier MTA/-IMAP] as well).

[...]

[1] Michael Loftis wrote (about qmail):

First is, unless they've made design changes, it's trivial to DoS.


Really? How would you DoS qmail? Could the same attack be used to DoS
postfix?

[2] Michael Loftis also wrote (about qmail):

Second, it doesn't scale so well, but unless you're talking upwards
of about 3-5k/msgs/hr you might not run into it.


Really? Quoting Bernstein quoting Bill Weinman
(cr.yp.to/qmail/users.html): "Our busiest list is about 250 messages
X 1800 subscribers (avg mail deliveries: 450,000 transactions per
day). Sendmail was barfing badly on this, and qmail seems to be doing
real well. The machine is a Pentium 90 running Linux 2.0.13 with 64Mb
of RAM. I have the spawn limit set at 100. I am *very* impressed."

How was the qmail that didn't scale well configured? On what
hardware?

See _my_ #2. Qmail _may_ scale well, but it *doesn't* in standard configuration. Did I mention that nobody with a clean mind runs critical and I/O intensive tasks on such hardware?

[3] Craig Sanders wrote:

ps: qmail is a bad idea.  postfix is better.

Your conclusion may be right, but the arguments are missing. Would
you please share?

I agree. Both statements.

Thomas



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