Bug 253738 – Registration message marked as spam by SpamAssassin

• Status: RESOLVED LATER
• Product: Gentoo Infrastructure

[Description NiTr0 2009-01-04 16:05:08 UTC]

After registration I receive registration message, but SpamAssassin marks it as spam - all spampoints are gathered by header&body content.

Reproducible: Didn't try

Steps to Reproduce:
1. Enter to http://forums.gentoo.org/index.php from IPs that detected as russian
2. Try to register with mailbox which has SpamAssassin filter that is just marking spam
3. Receive registration mail and look at header's fields that added by SpamAssassin

Actual Results:  
5.7 points of spam score

Expected Results:  
Normal processing (0 points)

Header from message (mail client Mozilla Thunderbird):

Return-path: <[e-mail]>
Envelope-to: [e-mail]
Delivery-date: Sun, 04 Jan 2009 16:53:04 +0200
Received: from smtp.gentoo.org ([140.211.166.183])
	by mail.seti.kr.ua with esmtp (Exim 4.68)
	(envelope-from <[e-mail]>)
	id 1LJULd-0005vG-0z
	for [e-mail]; Sun, 04 Jan 2009 16:53:03 +0200
Received: from dove.gentoo.org (dove.gentoo.osuosl.org [140.211.166.170])
	(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
	(No client certificate requested)
	by smtp.gentoo.org (Postfix) with ESMTP id 4601365331
	for <[e-mail]>; Sun,  4 Jan 2009 14:52:28 +0000 (UTC)
Received: from apache by dove.gentoo.org with local (Exim 4.69)
	(envelope-from <[e-mail]>)
	id 1LJUL6-0001yB-6j
	for [e-mail]; Sun, 04 Jan 2009 14:52:28 +0000
To: [e-mail]
Subject: а�аОаБб�аО аПаОаЖаАаЛаОаВаАб�б� аНаА б�аОб�б�аМб� Gentoo Forums
Reply-to: [e-mail]
From: [e-mail]
Message-ID: <[e-mail]>
MIME-Version: 1.0
Content-type: text/plain; charset=UTF-8
Date: Sun, 04 Jan 2009 14:52:28 +0000
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: PHP
X-MimeOLE: Produced By phpBB2
X-FGO-type: 
Content-Transfer-Encoding: quoted-printable
X-Spam-Score: 5.7 (+++++)
X-Spam-Report: Spam detection software, running on the system "server6", has
	identified this incoming email as possible spam.  The original message
	has been attached to this so you can view it (if it isn't spam) or label
	similar future email.  If you have any questions, see
	the administrator of that system for details.
	Content preview:  а�аОаБб�аО аПаОаЖаАаЛаОаВаАб�б� аНаА б�аОб�б�аМб� Gentoo Forums
	а�аОаЖаАаЛб�аЙб�б�аА, б�аОб�б�аАаНаИб�аЕ б�б�аО б�аОаОаБб�аЕаНаИаЕ. а�аАб�аАаМаЕб�б�б�
	аВаАб�аЕаЙ б�б�б�б�аНаОаЙ аЗаАаПаИб�аИ б�аАаКаОаВб�: [...] 
	Content analysis details:   (5.7 points, 5.0 required)
	pts rule name              description
	---- ---------------------- --------------------------------------------------
	1.5 SUBJ_ILLEGAL_CHARS     Subject: has too many raw illegal characters
	2.9 TVD_SPACE_RATIO        BODY: TVD_SPACE_RATIO
	1.3 SUBJECT_NEEDS_ENCODING SUBJECT_NEEDS_ENCODING
X-Spam-Flag: YES

[Comment 1 Anders Hellgren 2009-01-04 16:34:36 UTC]

I'm afraid there's nothing we can do with this, It's your mail server that marks the message as spam, not our.

[Comment 2 NiTr0 2009-01-04 17:02:27 UTC]

Trouble isn't in mail server, trouble is in headers - in "From:" isn't specified encoding. There is a good "Subject:" line from other UTF8 message:

Subject: =?UTF-8?B?0JLQvtC50L3QsCDQn9C70LXQvNGR0L0gLSA=?= =?UTF-8?B?0J3QtdCw0LrRgtC40LLQvdC+0YHRgtGMLg==?=

And there are lines from other correct formed message (exim as SMTP + Roundcube as mailer):

From: =?UTF-8?Q?=D0=A0=D0=BE=D0=BC=D0=B0?= <[e-mail]>
To: [e-mail]
Subject: 1121
Organization: =?UTF-8?Q?=D0=9A=D0=9A=D0=A1?=

As you can see, in good headers there is an encoding specifier in all header lines that contain non-English characters.

Of course, I can tune my filters, but IMHO there is a possibility of troubles with mailservers that drop junk mail.

[Comment 3 Anders Hellgren 2009-01-04 19:31:30 UTC]

There will be no change to our e-mail headers before we move to phpBB3 which contains a function to properly(?) encode the Subject header.

Note also that the header is only part of your spam score.

[Comment 4 NiTr0 2009-01-04 19:42:01 UTC]

Yes, I saw that SpamAssassin also doesn't like quoted-printable body...