Hi,
I've encountered a minor bug in Exim when it generates the Sender:
header on locally generated mails.
The Sender: consists of the following components:
Sender: "<name found in /etc/passwd>" <login@hostname>
The problem now comes up, if the name found in /etc/passwd contains a
quote. For instance if the name would be 'M\"atthias Waffenschmidt'
(you get the idea: some people use the entry in /etc/passwd for tex
templates...) the resulting header is:
Sender: "M\"atthias Waffenschmidt <mw@???>
Thus one quote is missing.
I encoutered this behaviour, when a mail bounced with
550 Syntax error in address headers
This is a nexample of why it is really dangerous to deny mails using
the ACL require verify = header_syntax (hello Tony...) because also
Exim rejects its own mail with:
rejected after DATA: unmatched doublequote in local part: failing address in "Sender" header is: "M\"atthias Waffenschmidt <mw@???>
OK, it's not very common to use a quote inside /etc/passwd, but if
Exim generates headers from this source, it is responsible that the
header is syntactically valid.
BTW: This is Exim 4.34 on FreeBSD
--
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Matthias Waffenschmidt | Ruppmannstr. 27 | fax +49 711 90074-33
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