LWN: Comments on "Fedora keeps sendmail — for now"

Fedora keeps sendmail — for now

zx2c4 — 2013-08-27T17:38:01+00:00

I got the impression, for some reason, that ssmtp was mostly abandoned and that msmtp was it's modern replacement. Are you still maintaining ssmtp? AFAIK, Gentoo has switched its default MTA away from ssmtp to msmtp.

Enough

cas — 2013-08-17T15:38:26+00:00

sure, but that's "attack" (singular) followed by retaliation - self defense is not an attack.

Enough

corbet — 2013-08-17T13:05:31+00:00

Please... It's starting to feel like an elementary school playground here. Could I ask everyone to relax a bit and hold off on the personal attacks?

Fedora keeps sendmail — for now

anselm — 2013-08-17T11:43:31+00:00

configuring an MTA to use a smarthost/relay/mail-server with authentication is NO MORE DIFFICULT than doing exactly the same thing in an MUA.

I'm not so sure. Kmail, for example, will probe a SMTP server for the best way to connect, including encryption and authentication. All the user needs to provide is the SMTP server's name and possibly their own user name and password for SMTP AUTH – and they get to put that into a reasonably obvious to find, convenient, and straightforward GUI dialog. It is also easy to maintain different »identities« with their own methods of sending mail to different submission servers, and to select between these when composing a message.

Getting an MTA like Sendmail or Postfix to do the same usually involves figuring out which of a set of fairly obscure configuration files to edit, which parameters to tweak in which way, and so on. Normally you get to edit at least two different text files and may even have to remember to run a file through some command-line program in order to put it into the binary database format that the MTA will actually look at. With most MTAs, it is possible to assign different sender addresses their own smart hosts etc., but doing so for a given MTA – even a fairly straightforward one like Postfix – is way more than people will be happy to have to learn just to be able to send e-mail.

In a distribution like Debian, the popular MTAs do come with a setup method that lets the installer pick one of a small number of alternatives (directly connected to the Internet/connected via a smart host/local mail only/…) but they fall far short of what is actually required in practice these days. There is ample scope for a user-facing mail configuration method that would collect mail submission information in a way that is not specific to any MUA/MTA, and would support package-specific »backends« that generated appropriate configuration settings for whichever software people are using on any given system.

Fedora keeps sendmail — for now

cas — 2013-08-17T08:04:57+00:00

no, there's nothing to understand because you're still pretending that that is an issue that affects *ONLY* an MTA, that MUAs are somehow magically immune.

you are either mistaken or being deliberately deceptive. i'll give you the benefit of the doubt and assume you just haven't thought it through.

configuring an MTA to use a smarthost/relay/mail-server with authentication is NO MORE DIFFICULT than doing exactly the same thing in an MUA.

Fedora keeps sendmail — for now

cas — 2013-08-17T08:01:57+00:00

actually, it's you that's the arsehole.

and an ignorant fuckwit, too.

Fedora keeps sendmail — for now

smurf — 2013-08-15T15:45:26+00:00

Please think before replying.

The default email installation works by looking up an MX record and connecting to port 25 there.

The default firewall of almost every home OR corporate user explicitly blocks port 25 because too many viruses and worms install too many spambots on too many Windows systems with nonexistent or broken security.

Do you NOW understand why installing a standard Unix-style mailer no longer make sense?

Most home users no longer even have a smarthost they could use without SMTP authorization, so even if people knew what a smarthost is (which they typically don't) asking them about that at installation time will not be helpful.

Fedora keeps sendmail — for now

Tester — 2013-08-15T15:31:26+00:00

We already have a binary format for configuration, it's called dconf and it's used by the GNOME desktop.

Fedora keeps sendmail — for now

nye — 2013-08-15T13:50:28+00:00

>here, let me google that for you. answering trivial FAQs for you is my entire purpose in life. i'll get back to you with a complete report as soon as i have nothing more important to do.

Except apparently ranting insanely about how your absurdly inconsequential use case should be the default inflicted upon millions of people, who would both need to spend the time reconfiguring their system to a semblance of sanity, assuming they somehow *know* that their system was configured by a selfish lunatic by default.

Christ, what an asshole.

Fedora keeps sendmail — for now

dlang — 2013-08-13T10:02:26+00:00

i don't think that you would find anyone who is opposed to such a tool being created.

Just the work of identifying the different types of access, enumerating them, and maintaining a list of per-ISP configs would be of immense value.

then configuring MTA or MUA software from that data would be much easier.

and by the way, as long as the actual work of configuring the MTA/MUA was modular and scriptable, this would also fit into the "Unix way" quite nicely :-)

Fedora keeps sendmail — for now

anselm — 2013-08-13T08:48:57+00:00

But that still leaves you out in the cold if your ISP wants you to submit mail to port 587 with TLS and SMTP AUTH. You will need to configure that manually – in a manner that depends on your specific MTA – after the installation.

The fact remains that ISP mail setups are diverse enough that any method of getting mail off the local machine – via a local MTA or an MUA – requires configuration. Instead of debating whether a system should come with a full-blown MTA like Sendmail by default, it would arguably be more productive to come up with a standardised scheme of representing ISP mail setups such that a user could be asked »What is your e-mail address (and possibly submission password)?« and the system could figure out automatically, for a reasonable majority of common ISPs, how to configure the local MTA or MUA of the user's choice to actually send mail using whatever access method that ISP supports, including goodies like encryption if it is available.

Fedora keeps sendmail — for now

mattdm — 2013-08-13T03:36:07+00:00

> Fedora also has a "minimal" install (@core) which is exactly the same thing: just enough to boot and install packages.

Well, it has more than that. For example, it had sendmail in it before we decided, with this change, to remove it from that set.

Fedora keeps sendmail — for now

mjg59 — 2013-08-12T22:46:25+00:00

"and as i said several times previously, you can't depend on the MUA being configured or working either."

Yup. As a result, email's a poor default for reporting things, and so josh is trying to fix the fact that there are still things in Debian that default to logging via email. As you've demonstrated, it's easy to bridge from syslog to email if you know that your local configuration supports that.

Fedora keeps sendmail — for now

cas — 2013-08-12T22:37:29+00:00

and as i said several times previously, you can't depend on the MUA being configured or working either.

just saying "it's too hard" and giving up is not a solution.

to configure either an MUA or an MTA there's a certain minimum amount of knowledge and understanding (or at least facts, like the smarthost name or IP address) required.

the same questions will be asked of the user, and a useful answer required - whether that's asked in a dialog/whiptail popup, a GUI dialog, or a plain tty style.

also, some here seem to think that only a GUI or ncurses app is an MUA. or that only automated scripts, cron job need to send mail via command-line interface.

/usr/sbin/sendmail *IS* an MUA. as is /usr/bin/mail. I can use them to send useful information to any email address....and I can do it reliably and conveniently, with consistent and documented command-line options.

grep foobar /var/log/something.log | sendmail me@somewhere.example.com

that's using an MUA. if i want to get fancy, i can use other command-line tools to compress the log extract and send it as a properly formatted mime-attachment.

Fedora keeps sendmail — for now

mjg59 — 2013-08-12T22:00:53+00:00

This discussion started with you claiming "the whole point of having /usr/sbin/sendmail on a system (whether that's provided by sendmail, exim, postfix, ssmtpd or anything else) is that other programs don't have to know how to route or deliver mail, they just pipe it to /usr/sbin/sendmail." Perhaps that's how it should be - there are clear benefits to things being configured in one place, and there are clear benefits to not reimplementing SMTP dozens of times. But, unfortunately, that's not how it is. If you want to send mail, you can't depend on the sendmail command.

Fedora keeps sendmail — for now

mjg59 — 2013-08-12T21:56:13+00:00

Exim's still installed by default, it's just not configured to do remote delivery.

Fedora keeps sendmail — for now

cas — 2013-08-12T21:53:46+00:00

and the user will have just as much (or more) difficulty configuring an MUA to work around the block.

stop pretending that this is the MTA's fault.

Fedora keeps sendmail — for now

cas — 2013-08-12T21:48:59+00:00

if that's the case, it would only be because people like you have succeeded in having an MTA (the default used to be exim) excluded from the default install. and then to add insult to injury you triumphantly claim "look, it doesn't work, i told you so!".

if that's the case then i wouldn't have noticed because i always install postfix instead of exim. and i can assure you that when you do install an MTA in debian, it does indeed offer to create a basic configuration for you with about 4 or 5 options for you to choose from - one of which is "send all mail through a smarthost"

Fedora keeps sendmail — for now

mjg59 — 2013-08-12T21:48:18+00:00

Sigh. No, that's not what I'm saying. What I'm saying is that you can't depend on there being a system-wide MTA that can deliver to the outside world, and as such any software that's expected to run on arbitrary machines cannot rely on the sendmail command doing anything useful.

Fedora keeps sendmail — for now

dlang — 2013-08-12T21:45:10+00:00

since you are saying that this has to work without any configuration step, I'm surious as to what MUA you are using that works without any configuration.

Fedora keeps sendmail — for now

mjg59 — 2013-08-12T21:40:59+00:00

The vast majority of residential ISPs block outgoing port 25 traffic, and those that don't will probably still be unable to deliver mail because their IP blocks will be in SORBS. This isn't a contrived example. This is the common case.

Fedora keeps sendmail — for now

cas — 2013-08-12T21:33:10+00:00

oh no! the sky is falling! an ISP that blocks smtp makes sending mail difficult. and it's all the MTA's fault.

this is even more contrived than the last example someone posted.

it's also a good example of why a local MTA is useful...you've got a lot more tricks up your sleeve to work around blockage with an MTA than you have with an MUA.

next up, "try to send mail from a laptop with a dead battery, during a power outage with no wifi or wired network available. you can't, see! and it's all the stupid MTA's fault".

Fedora keeps sendmail — for now

mjg59 — 2013-08-12T21:25:26+00:00

Having just performed a Debian install, I can assure you that it isn't.

Fedora keeps sendmail — for now

dlang — 2013-08-12T21:10:32+00:00

that configuration is done during the install, as others have pointed out.

Fedora keeps sendmail — for now

mjg59 — 2013-08-12T20:59:00+00:00

That would be an additional configuration step, so it doesn't answer my question.

Fedora keeps sendmail — for now

dlang — 2013-08-12T20:55:50+00:00

If you set the Debian install to use your ISPs mail server as it's smarthost, then yes, you probably can send mail to arbitrary addresses on the Internet (at least, if you send them from an e-mail address your ISP assigned to you)

Fedora keeps sendmail — for now

josh — 2013-08-12T15:49:50+00:00

>> I said a MUA, not a shell script.

> you're making an arbitrary and false distinction. any script that sends mail is a (primitive) MUA - pretty graphics or even an ncurses interface are not required.

The difference is that the MUA is the program the *user* invokes when they want to send mail.

MTAs can work nicely for fully automated mail (when configured appropriately on a network that supports them). Not every user wants or needs fully automated mails sent on their behalf; in particular,

To put it bluntly: I don't *want* sendmail to work on my system, because then programs might go around thinking they get to send mail without my involvement. You're arguing as though every single system has a pile of programs with a legitimate reason to send mail, which might have been true on UNIX systems of yore, but is no longer true on a modern Linux system.

In any case, I'm not going to spend time arguing the merits of modern mail clients. MTAs have a target audience of mail server administrators. MUAs have a far broader target audience, and the authors of modern MUAs spend far more time on UX and ease of use. If you believe that both are equally easy to configure, I have no interest in trying to convincing you otherwise.

Fedora keeps sendmail — for now

mjg59 — 2013-08-12T14:05:36+00:00

Perform a stock Debian install, performing no additional configuration steps. Connect this computer to a standard residential internet connection which blocks outgoing port 25 (as the vast majority do). Are you able to send email to arbitrary email addresses?

Fedora keeps sendmail — for now

Cyberax — 2013-08-12T11:47:49+00:00

Actually, what is a mailserver? Most people simply don't care - they want their systems work reliably and with minimal setup.

You know, fanboys like you is a major factor that'd been limiting Linux desktop for many years.

Fedora keeps sendmail — for now

cas — 2013-08-12T11:35:10+00:00

> What IS a smarthost?

what is a mail server? what is a mail relay? how many facetious questions can you ask in the name of pretending ignorance?

Fedora keeps sendmail — for now

cas — 2013-08-12T11:33:16+00:00

> it's far easier to tell your MUA "my mail server is over there".

it's nowhere near as difficult as you are pretending it is.

it's far easier to tell your MTA *once only* "my smarthost is there", than to have to configure the same information in every program that needs it - and then to re-configure them all when you change ISP or mail provider. or when you realise you need to handle work mail differently to personal mail.

> However, many Linux distributions are trying to optimize for
> user-friendliness these days,

the mistake you and your ilk are maing is assuming that "user-friendly" equals "crippled and dumbed-down". it's the same mistake microsoft made in the 80s...that apple managed to avoid until the late 90s.

if you want a system like that, there are several available - you don't need to turn linux into a clone of mac or windows. OS X is actually a pretty good system.

really, if you hate unix or linux that much, why do you even try to use it? use something else that suits your needs better instead of trying to ruin the things about linux that make it good.

Fedora keeps sendmail — for now

cas — 2013-08-12T11:24:25+00:00

> I said a MUA, not a shell script.

you're making an arbitrary and false distinction. any script that sends mail is a (primitive) MUA - pretty graphics or even an ncurses interface are not required.

> There's an "xdg-email" command which opens a draft mail in the user's
> preferred mail client.

xdg-* just defines the default MUA installed. it doesn't tell another app or script which MUA the user actually uses, and which one is actually configured.

nor does it tell a potential calling-app/script what command line options it has - i notice you completely ignored my point that /usr/sbin/sendmail provides standard and well-documented command-line options for other programs to use to send mail, whereas thunderbird (for example) does not...and (according to --help) doesn't even seem to be capable of doing that.

since not all MUAs actually provide that function, it's crazy to say "/usr/sbin/sendmail isn't needed, just use an MUA". "use something that *might* work if you're lucky" is not a solution, it's broken.

> I'd also point out that you seem to be taking personal offense at
> the idea that your preferred mode of operation might not be the
> perfect default for everyone. Nobody's talking about removing MTAs;

no, i'm taking offence at short-sighted idiocy, lack of understanding of systems design, and the contempt for users that you are displaying ("they're too dumb to understand that"). users aren't as stupid or as incompetent as you claim.

Fedora keeps sendmail — for now

Cyberax — 2013-08-12T11:14:09+00:00

So care to answer?

A significant majority of home users simply can not send email using plain SMTP. What are you proposing to do?

Fedora keeps sendmail — for now

Cyberax — 2013-08-12T11:12:59+00:00

> I have no idea, because I have no idea what you actually did or didn't do.
I described it - I took a stock Ubuntu image, installed it in a VM and tried to send a mail.

What exactly you don't understand?

>any user who finds answering a single question at install-time ("what's your smarthost?")
What IS a smarthost?

Fedora keeps sendmail — for now

cas — 2013-08-12T11:10:59+00:00

mmmm yum. i love the taste of strawman

Fedora keeps sendmail — for now

cas — 2013-08-12T11:10:06+00:00

> WHAT IS FREAKING 'CONTRIVED' IN THIS EXAMPLE???

I have no idea, because I have no idea what you actually did or didn't do. neither do i have any idea how dumb you're pretending to be to prove your point, or how dumb you actually are.

what i do know is that configuring an MTA to do a trivial task like sending an email from a desktop or laptop to an address @gmail.com is NOWHERE NEAR AS DIFFICULT AS YOU ARE PRETENDING IT IS. If it didn't work, it's because you deliberately broke it.

> So you're proposing that we keep a _broken_ interface, that is
> impossible for normal users to configure

it's nowhere near impossible. for simple stuff like you claim to have tried, it's trivial.

any user who finds answering a single question at install-time ("what's your smarthost?") too difficult is going to have *exactly* the same comprehension problem answering the same question for their pretty GUI MUA.

Fedora keeps sendmail — for now

josh — 2013-08-12T02:35:26+00:00

Systems privileged to act as mail servers, running on an IP that's not blacklisted, on a network that allows outbound unencrypted SMTP to random MXes, and maintained well enough to actually maintain reasonable deliverability metrics, are the vanishingly small special case compared to end-user client systems. Maintaining such a system requires non-trivial expertise. Congratulations, it sounds like you have it. Don't assume every random end-user does; it's far easier to tell your MUA "my mail server is over there".

Every single person I know who maintains a mail server on their personal system has had at least one incident where they either lost mail or had it delayed for days stuck in a mail queue somewhere. Life's too short. If you want to run your own mail server, please go right ahead; nobody is stopping you. However, many Linux distributions are trying to optimize for user-friendliness these days, not just flexibility and applicability to every possible use case. (See also http://islinuxaboutchoice.com/ .)

Fedora keeps sendmail — for now

josh — 2013-08-12T02:27:58+00:00

>> A MUA just needs to speak SMTP(S) to send mail, no other protocol.
>> And that's no crazier than expecting every app to fork and exec
>> sendmail to send mail; it's just different.

> worse, it makes sending mail from shell scripts far more difficult

I said a MUA, not a shell script. I don't expect shell scripts to speak SMTPS (though something like Python or Perl certainly can). See below.

>> Any app other than the user's a MUA that wants to send mail on
>> behalf of the user can invoke the user's MUA to do so

> and how, exactly, is another app or script supposed to figure out which
> MUA the user uses?

There's an "xdg-email" command which opens a draft mail in the user's preferred mail client. Desktop environments also have standard mechanisms of asking what program they should run, which they use to implement the "Send via email" commands and similar.

I'd also point out that you seem to be taking personal offense at the idea that your preferred mode of operation might not be the perfect default for everyone. Nobody's talking about removing MTAs; the question is whether a desktop Linux distribution might want to optimize for the single-user desktop use case.

Fedora keeps sendmail — for now

Cyberax — 2013-08-12T02:22:34+00:00

I made a test on my home Internet connection. Same result.

Or do you argue that home users are just a filth that doesn't merit attention of developers? Maybe we should care only about 'serious' users?

Fedora keeps sendmail — for now

Cyberax — 2013-08-12T02:21:21+00:00

> your one contrived example does not constitute extraordinary proof of an extraordinary claim.
WHAT IS FREAKING 'CONTRIVED' IN THIS EXAMPLE???

I got a Ubuntu 13.04 CD image, installed it in a VM and tried to send an email. I have a bog-standard home Internet connection and I haven't performed anything outstanding at all.

So you're proposing that we keep a _broken_ interface, that is impossible for normal users to configure and that hasn't worked for ages. All in the name of 'unixyness'.