著者: Steven Chamberlain 日付: To: Renaud Allard CC: Exim-dev 題目: Re: [exim-dev] Delivering message to Exim via SMTPS with LF instead
of CRLF, breaks DK validator
Renaud Allard wrote: > Is this really a bug considering RFC2821 says:
>
> 2.3.7 Lines
>
> SMTP commands and, unless altered by a service extension, message
> data, are transmitted in "lines". Lines consist of zero or more data
> characters terminated by the sequence ASCII character "CR" (hex
> value 0D) followed immediately by ASCII character "LF" (hex value
> 0A). This termination sequence is denoted as <CRLF> in this document.
I understand that mail *should* (or MUST in RFC terms) be delivered with
CRLF endings. But by abusing that rule I seem to be able to deliver
messages which skip DK validation and pass otherwise unhindered, which
seems to be a problem.
> Conforming implementations MUST NOT recognize or generate any other
> character or character sequence as a line terminator.
In that case, maybe the DK validator should ignore the From: header
as being syntactically incorrect, as it contains \n characters. At
present it's reading a corrupted dk_sender instead.
When the message reaches my Maildir it still has LF instead of CRLF
endings. Perhaps Exim is doing the right thing by delivering it,
because the mailbox address is given correctly with the SMTP commands.
I notice that SpamAssassin is happy to scan the message as if it were
syntactically correct, though. That could imply that either SA-Exim or
SpamAssassin are breaking the above rule.
Likewise, Mozilla Thunderbird is happy to display the message when
I access it via Dovecot IMAP. Unless Dovecot is converting the LF's to
CRLF, then maybe Mozilla Thunderbird is in contravention of the RFC also.
Maybe I've simply hit part of the:
> ...long history of causing problems in mail implementations and
> applications that use the mail system as a tool.
