Quoting Ian C. Sison ([EMAIL PROTECTED]):

> And of these points not a single ONE of these address anything
> technical in nature,

Technical comparisons of MUAs are difficult; meaningful ones, more so,
because much is inherently debatable.  Even the comparisons of
throughput capacity I've seen have been such.  (See remarks by J C
Lawrence near the end of
http://www.grin.net/~mirthles/pile/contra_majordomo_plus_MTA_stuff.html)

Qmail (like Postfix) benefits from carefully modular design, with
attention paid to trust relationships and the nature of inter-modular 
communication.  (By comparison, both Sendmail and Exim both spawn as
SUID-root processes, then drop privilege according to the role of each
process.  Many comments commonly seen about Sendmail are outdated in
failing to credit it with that improvement.)  

Per J C Lawrence, Qmail, Postfix, and Exim all seem to generate similar
throughput numbers, with difference in system loading characteristics.
Sendmail's in the same ballpark, but with less well optimised delivery 
and spooling.  (Again, it's alleged that Sendmail's been improved in
those areas.)

Postfix and Exim both support all of sendmail's command-line modes,
which means either is a drop-in replacement (once you have a suitable
conf file).  To the best of my recollection, qmail doesn't.  (There may
be a patch.)  

Qmail includes support only for maildir format.  Fine if you have
decided to go all-maildir; a pain otherwise.  Again, there may be a
patch.

Patches:  Because of Dan's licensing (see below), third-party qmail
patches effectively never get regression tested against one another.

Sendmail sports the Configuration File from Hell -- which in theory you
can avoid by working only with m4 files.  But somehow, everyone keeps 
getting sucked back into directly modifying sendmail.cf .

Arguments based on security history are dubious, for multiple reasons
including failure to take into account fundamental changes after some
past incidents.  (If one were to judge MUAs on the basis of past
exploits, then the newest MUA would automatically win without regard to
merit.)

Build problems:  Exim is/was reputed to use a rather eccentric and brittle
Makefile setup.  (Can't comment, and if this was true, I'm not sure it
still is.)  Qmail suffers the peculiarity that DJB doesn't believe in
automake/autoconf _at all_, and consequently his coding style is really 
whacked and difficult to read, let alone port.

Both Qmail and Postfix have easy virtual host support, and in general
have administrative characteristics that scale well to large sites.
Exim's configuration/administration is perfect for small sites.
The configuration files for qmail one either loves or hates; they're
eccentric, in any event.

Qmail's mail spool cannot be backed up or migrated to a different host,
because it uses inode numbers.  (Dan feels this is justified for
performance reasons.)

Last, of course, qmail is the only one of the four under a proprietary 
licence -- the main consequence of which is that the project cannot be
forked, and that if/when Dan loses interest or dies, without some
additional licence grant the package will become effectively
unmaintainable and a dead project.

-- 
Cheers,                                             Live Faust, die Jung.
Rick Moen
[EMAIL PROTECTED]
_
Philippine Linux Users Group. Web site and archives at http://plug.linux.org.ph
To leave: send "unsubscribe" in the body to [EMAIL PROTECTED]

Fully Searchable Archives With Friendly Web Interface at http://marc.free.net.ph

To subscribe to the Linux Newbies' List: send "subscribe" in the body to 
[EMAIL PROTECTED]

Reply via email to