[Mailman-Users] sendmail bounces

[Brad Knowles]

At 2:56 AM +0800 2004-09-09, David Cake wrote:

>  	I really am beginning to run out of ideas.

	On problems like this, I inevitably have to log onto the machine 
and try various different bits of debugging until I finally stumble 
across the problem.  No amount of remote debugging advice I can 
provide is likely to be of much help.

>                                 He must, at least, bear some
>  responsibility for the extraordinary difficulty of diagnosing why
>  sendmail won't do what it should, though.

	Eric has been trying to replace sendmail for many years. 
Unfortunately, he's fighting the inertia of all the systems vendors 
and most of the entire Internet itself.  He never gets the time he 
wants/needs to work on Son-Of-Sendmail.

>  	Yes, indeed, I do not. But I can blame sendmail for being an
>  overcomplex, incomprehensible, hard to debug, sanity damaging nightmare.

	Debugging sendmail can be a bitch.  Eric himself keeps copies of 
Bryan's book around, because even he can't keep the whole thing in 
his head.  This is not entirely his fault.  It has grown over the 
years, and has accumulated a great deal from a wide variety of 
sources.  He's never had the opportunity to do a complete ground-up 
redesign.  Other authors have not had that problem.

>  	Don't get me wrong, I appreciate the pioneering efforts of those
>  involved in the creation of sendmail (and .oz.au for that matter), but
>  not having to live with certain dubious design decisions decades later.

	Believe me, I understand.  I found out about postfix back when it 
was still called VMailer, and Wietse and I were going to be giving 
back-to-back talks at SANE'98.  There are a lot of other programs 
which have a lot of advantages over sendmail.

	Indeed, there are no other MTAs around currently in common use 
which have such a long legacy.  This is both a testament to the power 
of sendmail, and an albatross hanging around it's neck.

>  	Just a couple more weeks and my last sendmail server moved to postfix.
>  Can't wait. But will I ever get mailman working in the meantime.

	For setting small to medium-size mail systems, postfix is the MTA 
I strongly recommend.  It has the most easy-to-understand 
configuration file syntax I've ever seen (which can result in a 
configuration file that is truly useful with just two lines), is 
default secure out of the box, is easily managed and monitored, and 
is just about an ideal configuration out-of-the-box for most mailing 
list type functions.

	That said, sendmail is still more scalable, especially when it 
comes to scanning incoming e-mail for viruses and spam, and with 
proper configuration, it is possible to handle 90-99% of all e-mail 
passing through the system without the messages ever hitting the disk 
(except for those messages being delivered locally).  It takes more 
work to configure, monitor, and manage, but in the long-run, it is 
still more scalable.

>  ... I felt very ambiguous about
>  creating something which I looked at and said "This is a monstrosity
>  by almost any reasonable definition." - Eric Allman
>  How did this happen? I should have gotten wise and said, "Wait!
>  Something's wrong." - Eric Allman (referring to sendmail config file format)

	Eric has also said that he initially felt like he was trying to 
kill a fly with a sledgehammer, and this always seemed wrong to him. 
It wasn't until later that he realized that what he was really trying 
to kill was the elephant on which the fly had landed, and the 
sledgehammer wasn't really a big enough weapon to do that.

	He has spent the entire rest of his life trying to rectify that problem.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.