Ответ: SENDMAIL

[Rob Landley]

On Monday 30 June 2008 10:20:06 Denys Vlasenko wrote:
> On Sunday 29 June 2008 11:31, Vladimir Dronnikov wrote:
> > Q: I'm getting crazy of what people meant when they invented sendmail
> > interface: where sender address is supposed to be obtained from? From
> > OPTIONAL -f parameter? From 'From: ' header? From $USER being appended
> > by ?$HOSTNAME? From [user:pass@]host[:port]?! Mail servers require
> > ADDRESS not username to be passed with EHLO/HELO.
>
> Hehe. sendmail was a disaster. Harrowing tales
> of sendmail.cf format which resulted in lines consisting
> mostly of punctuation chars are still being told.
>
> IIRC it also had tons of security holes.
>
> The most sad part, I was reading an interview with the guy
> who wrote it. Neither interviewer asked "How on earth you decided
> to make such config format" etc nor the auther had guts
> to tone down interviewer and admit "well, actually take note that
> sendmail was written many years ago. I was not as experienced
> back then as I am today and sendmail's original design and code
> are not exactly too good. Today I'd do it much differently
> and better..."
>
> In reality, interview was all rosy and sendmail was obviously
> a cornerstone of Unix and a gem of programming art...

Sendmail is a relic that's finally going the way of the original Netscape 
browser.  The number of sites running sendmail has declined significantly 
over the past few years, last year sendmail use had fallen to about 12%:

http://www.oreillynet.com/pub/a/sysadmin/2007/01/05/fingerprinting-mail-servers.html

Postfix is #2, followed by Google's Postini, then Exchange...

I wouldn't look at how sendmail does anything for a model, I'd look how 
_postfix_ does it. :)

Rob
-- 
"One of my most productive days was throwing away 1000 lines of code."
  - Ken Thompson.