Re: [gentoo-user] Re: [OT] Setting up a fall back ISP SMTP in sendmail

[Alan McKinnon <alan.mckinnon@gmail.com>]

On Tuesday 20 April 2010 17:51:12 Harry Putnam wrote:
> Grant Edwards <grant.b.edwards@gmail.com> writes:
> > On 2010-04-20, Harry Putnam <reader@newsguy.com> wrote:
> >> About all the snipes concerning hacking sendmail.cf... I'm sure you
> >> are all aware that any hacking needs to happen in sendmail.mc... then
> >> let m4 sort out sendmail.cf.
> > 
> > IOW, sendmail has a configuration file so incomprehensible that the
> > configuration file needs a configuration file.
> 
> Internet mail is quite complex, yes.

This statement is the source of the confusion surrounding sendmail.

Internet mail is not complex, it is stunningly simple:

mail comes in,
look up where it should go,
send it there

In between you might hand the message off to virus and spam scanners, you 
might look up an ACL before accepting it coming in, but those are all 
additives to find valid mail. Remove the additives, and you get the amazingly 
simple lookup table scheme described above.

There isn't even an inherent difference between relays and final destination 
MTAs, they still send the mail somewhere. The difference is in the viewpoint 
of the sysadmin.


-- 
alan dot mckinnon at gmail dot com