Quoting Andrew Sackville-West <andrew@farwestbilliards.com>:
one of the symptoms of "user friendliness". Ubuntu, I assume, makes
the assumption that they are pulling in windows users who want a
windows type mail environment with MUA talking smtp and pop to
smarthosts out on the 'net at large instead of a local mail
distribution system. I'm sure there are other symptoms of a similar
nature where they are moving away from the *nix heritage in the
interest of user-friendliness. I wonder how that plays out in the long
run?
I have become a fan of the *nix philosophy and *nix heritage ever since
I started using Debian (about 3.5 years ago). However, this is one are
(mail distribution) where I do not agree. Each network should have some
specifically designated *outbound* mail exchangers. All other hosts
should be blocked from sending any outbound mail to the public net.
That is just part of being a good netizen. A while back I was getting
tons of spam from a host in the state government of New Mexico
netblock. It was somebody's laptop that got infected and started
relaying spam. That is ridiculuous.
The fact is that the majority of users lack sufficient knowledge to
properly admin an MTA. They should simply configure their systems to
point to their ISPs or organizations mail relays. I'm not saying that
local mail distribution is obsolete, just that a situation where every
host on a network can send email to the public Internet is part of the
problem we are currently experiencing.
When I still had SBC, they decided to block all outbound port 25
traffic. I was infuriated since I was paying for their Internet service
and didn't feel that I should have to opt-out of this port 25 block. I
was able to get them to ublock it when I explained to them that I wanted
to run my own mail server and that I knew what I was doing. Thinking
back, though, I realize it was a great idea from their part since most
users are clueless.
A distro targeted at clueless users (or the masses, or whatever other
euphamism you prefer), should take precautions not to create a situation
where they can easily mess up.