Date: Sat, 19 May 2001 16:02:15 +0200 From: Brad Knowles <brad.knowles@skynet.be> To: Jamie Bowden <ragnar@sysabend.org>, Brett Glass <brett@lariat.org> Cc: freebsd-chat@FreeBSD.ORG Subject: Re: Opera ports to QNX but not BSD Message-ID: <p0510030fb72c28b702d5@[194.78.241.123]> In-Reply-To: <Pine.BSF.4.10.10105182026310.13601-100000@moo.sysabend.org> References: <Pine.BSF.4.10.10105182026310.13601-100000@moo.sysabend.org>
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At 8:52 PM -0700 5/18/01, Jamie Bowden wrote:
> While I was by no means a top sendmail expert, I could and did regularly
> edit the cf file without bothering to grab the manual. I've never felt so
> good about dumping something that I spent so much time acquiring skill
> with.
As the former comp.mail.sendmail FAQ maintainer, a guy who's been
hacking around on sendmail for many years (indeed, most of the
anti-spam stuff available today is directly or indirectly based on
work I did while I was at AOL and contributed back), and being the
only person I know of to recently present two different papers on the
scaling of e-mail systems (based on sendmail) outside of employees of
Sendmail, Inc. (SANE '98 and LISA 2000), I believe I can safely say
that I am pretty familiar with sendmail.
Indeed, I can also say that I am pretty familiar with postfix. I
was involved on the mailing lists for postfix ever since it used to
be called "VMailer", and I believe that I have contributed materially
to the features that the program has today, as well as the way in
which things have been done internally within the program.
The conversion from sendmail to postfix is usually a pretty
simple one. Postfix comes configured, out-of-the-box, to be about as
secure as you can reasonably get, and all of the important factors
have reasonable defaults assigned to them. Indeed, one of the
original design goals for postfix was to be as much of a drop-in
replacement for sendmail as possible, with the sole exception of the
configuration file.
About 99.9% of the things you might want to typically do with an
MTA are relatively easily done in postfix, through table-driven
techniques. While sendmail may be the best documented and most
widely understood MTA in the world, I believe I can safely say that
postfix has the most easily understandable MTA configuration file in
the world, and newbies can easily do things in postfix that they
would never dream of doing with sendmail.
Moreover, because of the fact that Wietse was able to start with
a clean slate and design a new MTA using 20/20 hindsight with regards
to sendmail, he was able to do a lot of things in a much simpler and
more straightforward manner. He was also able to do things in a way
that would be more inherently secure, as well as being much more
easily scalable.
That said, if you have a more complex configuration, it is
possible that it would take quite a bit of work to convert to a
postfix equivalent, and if you're doing really esoteric things that
require writing your own customer sendmail.cf rules for things that
you can't normally do with sendmail, and aren't features that Wietse
Venema has already anticipated, it may even be impossible to get a
100% conversion.
In particular, anything with the new milter interface for
sendmail is probably simply not possible to replicate with postfix.
I can say that, at my previous employer, I ripped out sendmail on
our outbound machines and replaced them with postfix, and did a
rolling upgrade -- putting a new machine into service and then taking
an old machine out (to be upgraded), one at a time. The conversion
was about as smooth as it could get, and I later did the same for our
front-end inbound mail servers.
For simple configurations, replacing sendmail with postfix is
about as trivially easy as you can get. it's the more complex
configurations that may pose more of a problem.
--
Brad Knowles, <brad.knowles@skynet.be>
/* efdtt.c Author: Charles M. Hannum <root@ihack.net> */
/* Represented as 1045 digit prime number by Phil Carmody */
/* Prime as DNS cname chain by Roy Arends and Walter Belgers */
/* */
/* Usage is: cat title-key scrambled.vob | efdtt >clear.vob */
/* where title-key = "153 2 8 105 225" or other similar 5-byte key */
dig decss.friet.org|perl -ne'if(/^x/){s/[x.]//g;print pack(H124,$_)}'
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