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Posted to users@spamassassin.apache.org by vi...@itera.ru on 2008/03/31 18:27:03 UTC
[offtopic] Are 8-bit characters completely illegal in a raw message?
Hi to all.
Sorry for a OFFTOPIC but don't know where to ask this question. I need an
RFC's guru help :-)
So, as I've found in RFC's all header fields in message should be encoded
to 7-bit data. In addition my SMTP server does *not* support 8-bit MIME
for incoming e-mail.
The question is in subject - or am I missed some *legal* usage of 8-bit
characters (maybe some kind of comments, optional fields, etc)?
Of course, the goal is to write the rule for SA that will trigger on 8-bit
symbols in raw ("raw"="what I've seen in tcpdump output for this message")
message.
Thanks in advance. Vitas.
Re: [offtopic] Are 8-bit characters completely illegal in a raw message?
Posted by Matus UHLAR - fantomas <uh...@fantomas.sk>.
On 31.03.08 20:27, vitas1@itera.ru wrote:
> Sorry for a OFFTOPIC but don't know where to ask this question. I need an
> RFC's guru help :-)
>
> So, as I've found in RFC's all header fields in message should be encoded
> to 7-bit data. In addition my SMTP server does *not* support 8-bit MIME
> for incoming e-mail.
>
> The question is in subject - or am I missed some *legal* usage of 8-bit
> characters (maybe some kind of comments, optional fields, etc)?
>
> Of course, the goal is to write the rule for SA that will trigger on 8-bit
> symbols in raw ("raw"="what I've seen in tcpdump output for this message")
> message.
try RFC 1652
afaik, raw 8-bit in body is allowed, transfer must be supported by both
client&server, 8-bit in header is not allowed, must be encoded.
--
Matus UHLAR - fantomas, uhlar@fantomas.sk ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Depression is merely anger without enthusiasm.
Re: [offtopic] Are 8-bit characters completely illegal in a raw
message?
Posted by Derek Harding <de...@innovyx.com>.
On Mon, 2008-03-31 at 16:32 -0700, SM wrote:
> Hi Vitas,
> At 09:27 31-03-2008, vitas1@itera.ru wrote:
> >So, as I've found in RFC's all header fields in message should be
> >encoded to 7-bit data. In addition my SMTP server does *not* support
> >8-bit MIME for incoming e-mail.
>
> The message body should be 7-bit only as well. See RFC 2822.
Unless, as has already been mentioned, 8BITMIME is negotiated during the
SMTP transaction.
Derek
Re: [offtopic] Are 8-bit characters completely illegal in a
raw message?
Posted by SM <sm...@resistor.net>.
Hi Vitas,
At 09:27 31-03-2008, vitas1@itera.ru wrote:
>So, as I've found in RFC's all header fields in message should be
>encoded to 7-bit data. In addition my SMTP server does *not* support
>8-bit MIME for incoming e-mail.
The message body should be 7-bit only as well. See RFC 2822.
Regards,
-sm
Re: [offtopic] Are 8-bit characters completely illegal in a raw message?
Posted by Enrico Scholz <en...@sigma-chemnitz.de>.
Matus UHLAR - fantomas <uh...@fantomas.sk> writes:
>> > In addition my SMTP server does *not* support 8-bit MIME for
>> > incoming e-mail.
>>
>> That's very uncommon and lot of mail will be probably rejected
>> due to this.
>
> are there known problems with mailers that can send/receive
> 8-bit but can't encode to QP or base64?
exim causes such problems; it is not MIME aware and won't be able
to make such a conversion. So it will either violate RFC 2821
(which is done already by exim when generating bounces, btw), or
it will abort delivery when it does not see an '250-8BITMIME'
EHLO response.
Enrico
Re: [offtopic] Are 8-bit characters completely illegal in a raw message?
Posted by Matus UHLAR - fantomas <uh...@fantomas.sk>.
> vitas1@itera.ru writes:
> > In addition my SMTP server does *not* support 8-bit MIME for
> > incoming e-mail.
On 01.04.08 10:52, Enrico Scholz wrote:
> That's very uncommon and lot of mail will be probably rejected
> due to this.
are there known problems with mailers that can send/receive 8-bit but can't
encode to QP or base64?
--
Matus UHLAR - fantomas, uhlar@fantomas.sk ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Fucking windows! Bring Bill Gates! (Southpark the movie)
Re: Re: [offtopic] Are 8-bit characters completely illegal in a raw message?
Posted by vi...@itera.ru.
Thanks for all answers.
Matus UHLAR - fantomas <uh...@fantomas.sk> wrote on 01.04.2008 18:11:03:
> > vitas1@itera.ru writes:
> > > In addition my SMTP server does *not* support 8-bit MIME for
> > > incoming e-mail.
>
> On 01.04.08 10:52, Enrico Scholz wrote:
> > That's very uncommon and lot of mail will be probably rejected
> > due to this.
>
> are there known problems with mailers that can send/receive 8-bit but
can't
> encode to QP or base64?
My configuration is - Exim as a front-end (filtering) server for incoming
e-mail and Lotus Domino as a back-end.
Both don't support 8BITMIME. And I haven't any problems with 8-bit bodies
- Exim just passes them to back-end an then they are delivered to users in
correct/readable format.
The only problem is that such e-mail is usually spam :-)
Well I've found another interesting thing (sorry for offtopic again :-).
RFC2045 defines a term "preamble". Usually it looks like a phrase "This is
a multipart message..." in raw message and MIME-compatible software should
just ignore it.
According to RFC2045 and RFC2822 (as I understand them properly) preamble
MUST consist of US-ASCII characters.
But I see many 8-bit preambles in *ham* e-mail. I think this is because of
badly localized software at sending side. So *be careful* if you want to
score 8-bit characters - you can get some false positives!
Thanks again to all.
Vitas.
Re: [offtopic] Are 8-bit characters completely illegal in a raw message?
Posted by Enrico Scholz <en...@sigma-chemnitz.de>.
vitas1@itera.ru writes:
> So, as I've found in RFC's all header fields in message should
> be encoded to 7-bit data.
s/should/must/
> In addition my SMTP server does *not* support 8-bit MIME for
> incoming e-mail.
That's very uncommon and lot of mail will be probably rejected
due to this.
> The question is in subject - or am I missed some *legal* usage
> of 8-bit characters (maybe some kind of comments, optional
> fields, etc)?
Without extensions (RFC 1652), 8-bit in SMTP body is illegal.
> Of course, the goal is to write the rule for SA that will
> trigger on 8-bit symbols in raw ("raw"="what I've seen in
> tcpdump output for this message") message.
fwiw, sendmail has
| O EightBitMode=strict
rule. See
https://www.cvg.de/people/ensc/sendmail-8hdr.txt
for a rule to check headers.
Enrico