dovecot - Dec 2010 - Sieve rule issue with certain character sets

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I have a global sieve rule in place to filter mailing-lists. This has worked
well so far. Recently however one subscriber on a list seems to create strange
character set encodings in the 'From' and 'To' headers. This
leads to unprocessed/unfiltered mails (no errors thrown). Is this a
configuration or Pigeonhole issue (latest HG used)?

Headers from failing mail:

From: "=?UTF-8?B?VG9yaW50aGllbA==?=" <user at domain.tld>
To: "=?UTF-8?B?ImJpbmQtdXNlcnNAbGlzdHMuaXNjLm9yZyI=?="
	<bind-users at lists.isc.org>

Relevant sieve rule:

if allof (address :is ["To","CC"] ["bind-users at
lists.isc.org","bind-users at
isc.org","comp-protocols-dns-bind at isc.org"],
        header :contains "List-Id"
"bind-users.lists.isc.org")
        {
        fileinto "Public/Mailing-Lists/Bind-Users";
        }

Regards
Thomas

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iEYEARECAAYFAk0dvZ4ACgkQ+meF/S97aXgYTACfZC70bsYn3d4/VRY2GfK5lF0k
xOIAnRsBliv9EErA919vc5KoTAHhq3rC
=IE3C
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On 12/31/2010 12:25 PM, Thomas Leuxner wrote:
> I have a global sieve rule in place to filter mailing-lists. This has
> worked well so far. Recently however one subscriber on a list seems
> to create strange character set encodings in the 'From' and
'To'
> headers. This leads to unprocessed/unfiltered mails (no errors
> thrown). Is this a configuration or Pigeonhole issue (latest HG
> used)?
> 
I executed the following to investigate this issue:

###
sieve-test -t - -Tlevel=matching ~/frop.sieve ~/frop.eml

      ## Started executing script 'frop'
   3: address test
   3:   starting `:is' match with `i;ascii-casemap' comparator:
   3:   extracting `To' headers from message
   3:   parsing address header value `""bind-users at
lists.isc.org""
<bind-users at lists.isc.org>'
   3:   extracting `all' part from non-address value
`""bind-users at lists.isc.org"" <bind-users at
lists.isc.org>'
   3:   matching value `""bind-users at lists.isc.org""
<bind-users at lists.isc.org>'
   3:     with key `bind-users at lists.isc.org' => 0
   3:     with key `bind-users at isc.org' => 0
   3:     with key `comp-protocols-dns-bind at isc.org' => 0
   3:   extracting `CC' headers from message
   3:   finishing match with result: not matched
   3: jump if result is false
   3:   jumping to line 5
        ## Finished executing script 'frop'

Performed actions:

  (none)

Implicit keep:

 * store message in folder: INBOX

sieve-test(stephan): Info: final result: success
###

Apparently, the MIME-encoded part of those address headers includes
double quotes, duplicating the ones surrounding the encoded part
already. As can be seen from the above trace, this decodes into an
invalid address representation, causing Pigeonhole to handle it as
opaque text.

If those quotes are really supposed to be part of the 'phrase' part of
the e-mail address, I think those should have been escaped somehow. I
don't think that encoding can be an alternative for that. Timo, any
thoughts?

Regards,

Stephan.