Mailing List Archive

MIME things, queue management
Hi,

I have just installed qmail on my home computer, and am enjoying it..

There is a few things unclear to me. I'd like the 8BITMIME thing to
automagically convert MIME/8bit e-mail messages with appropriate headers
to Quoted-Printable/Base 64, if the other MTA isn't ESMTP/8BITMIME, like
sendmail does. I did a grep "quoted-printable" in the qmail sources, but
didn't find anything..

Secondly, how do I remove safely a message from the queue? And how do I
run only selected messages in the queue?

Hynek

--
Hynek Med, xmedh02@manes.vse.cz
Re: MIME things, queue management [ In reply to ]
> There is a few things unclear to me. I'd like the 8BITMIME thing to
> automagically convert MIME/8bit e-mail messages with appropriate headers
> to Quoted-Printable/Base 64, if the other MTA isn't ESMTP/8BITMIME, like
> sendmail does.

You can't do this with qmail.

> sendmail does. I did a grep "quoted-printable" in the qmail sources, but
> didn't find anything..
>
> Secondly, how do I remove safely a message from the queue?

Shut down, rm /var/qmail/queue/*/<r>/<q>, restart.

> And how do I
> run only selected messages in the queue?

Shut down, touch /var/qmail/queue/{local,remote}/<r>/<q>, restart.

If this is something you want to do on a regular basis, you should
probably be using serialmail instead.

Tim.
Re: MIME things, queue management [ In reply to ]
On Mon, 17 Feb 1997, Tim Goodwin wrote:

> > There is a few things unclear to me. I'd like the 8BITMIME thing to
> > automagically convert MIME/8bit e-mail messages with appropriate headers
> > to Quoted-Printable/Base 64, if the other MTA isn't ESMTP/8BITMIME, like
> > sendmail does.
>
> You can't do this with qmail.

OK, so when (if ever) will this be implemented to qmail? Otherwise I'll
have to switch back to sendmail. :-)

Hynek

--
Hynek Med, xmedh02@manes.vse.cz
Re: MIME things, queue management [ In reply to ]
> OK, so when (if ever) will [ 7bit <-> 8bit MIME conversions ] be
> implemented to qmail?

I can't speak for Dan, of course, but I believe the answer is "never".

Here are some of the reasons why I consider MIME conversions in an
MTA to be a Bad Thing. Unfortunately, this is a very religious area.
Expect this thread to degenerate into a long and fruitless flame war :-).

1. Layering violation. The function of an MTA is to relay messages
transparently.

2. Complexity. Correctly doing MIME conversions (including supporting
arbitrarily nested MIME messages, and dealing with non conformant
messages) is not straightforward. Doing conversions costs CPU, memory,
possibly disk, and maybe security. The first sendmail implementation
included a buffer overrun bug, which happened to allow a remote root
exploit.

3. Throughput considerations. It is only possible to discover whether
or not an SMTP server supports 8BITMIME when you are already halfway
through an SMTP transaction. This is not the ideal time to stop and
convert the message you wanted to send: see point 2.

4. User choice. A lot of people hate the quoted-printable encoding.
(Just because an MTA claims to support 8BITMIME, doesn't mean that all
the User Agents it can deliver to understand MIME: see point 1.)

5. Poor implementation. The way sendmail implements this is really
silly: the conversion is done only if the message already includes MIME
headers. Because of 4, some people are now *disabling* use of MIME
headers on their outgoing mail.

6. Better alternative. Although "just send 8" seems less reliable in
theory (due to the existence of SMTP servers that strip the top bit), in
practice it works well.

Tim.
Re: MIME things, queue management [ In reply to ]
At 02:41 PM 2/17/97 +0100, Hynek Med wrote:
>On Mon, 17 Feb 1997, Tim Goodwin wrote:
>
>> > There is a few things unclear to me. I'd like the 8BITMIME thing to
>> > automagically convert MIME/8bit e-mail messages with appropriate headers
>> > to Quoted-Printable/Base 64, if the other MTA isn't ESMTP/8BITMIME, like
>> > sendmail does.
>>
>> You can't do this with qmail.
>
>OK, so when (if ever) will this be implemented to qmail? Otherwise I'll
>have to switch back to sendmail. :-)

Actually, Tim is wrong (which is unusual for Tim). You *can* do this with
qmail, but the code to do it is not included with qmail. If you have code that
does the require unprintable transformation, you can (mostly) just pipe the mail
through it on the way to the mailbox.
-russ
Re: MIME things, queue management [ In reply to ]
At 08:16 PM 2/17/97 -0500, you wrote:
>> Actually, Tim is wrong (which is unusual for Tim). You *can* do this with
>> qmail, but the code to do it is not included with qmail. ...

Someone replied, in private mail:

>Can you really hook in conditionally during an SMTP session, and do one
>thing if it answered EHLO with 8BITMIME and another thing if not?

Ahhhh, sorry, I obviously didn't understand. I thought sendmail was rewriting
the message as stored in the user's mailbox, not while in transit. So Tim is right
(and I'm wrong), qmail can't munge messages in transit; not even if you want it to.
-russ