marf K. Li Internet-Draft B. Leiba Intended status: Standards Track Huawei Technologies Expires: January 3, 2012 July 2, 2011 Email Feedback Report Type Value : not-spam draft-ietf-marf-not-spam-feedback-00 Abstract This document defines a new Abuse Reporting Format (ARF) feedback report type value: "not-spam". It can be used to report a message that was mistakenly marked as spam. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on January 3, 2012. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Li & Leiba Expires January 3, 2012 [Page 1] Internet-Draft Email Feedback Type: not-spam July 2011 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Feedback Report Type: Not-Spam . . . . . . . . . . . . . . . 4 3. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.1. Normative References . . . . . . . . . . . . . . . . . . . . 6 7.2. Informative References . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 7 Li & Leiba Expires January 3, 2012 [Page 2] Internet-Draft Email Feedback Type: not-spam July 2011 1. Introduction In RFC 5965 [RFC5965], an Abuse Reporting Format (ARF) is defined for reporting email abuse. Currently two feedback report types are defined that are related to the spam problem, and that can be used to report abusive or fraudulent email messages: o abuse: indicates unsolicited email or some other kind of email abuse. o fraud: indicates some kind of fraud or phishing activity. This specification defines a new feedback report type: "not-spam". It can be used to report a message that was mistakenly marked as spam. 1.1. Discussion In some cases, the mail client receives an email message that was tagged as spam, either by the mail system or accidentally by the user, but the end user finds that actually it is not spam. The mail client accepts the end user's report instruction and retrieves information related to the message, and reports this email as not- spam to the mail operator. When the mail operator receives the report, it can determine what action is appropriate for the particular message and user. (The requirement for a not-spam report type is from the Open Mobile Alliance (OMA) Spam Report Requirement Document [OMA-SpamRep-RD].) For example, in response to a "not-spam" report the mail system can remove the spam tag or change the category, possibly preventing future similar mail for this user from being marked as spam. The report can be used to adjust the training of an automated classifier. After processing the report, the mail operator can send a notification to the mail client about the processing result. In most cases, "not-spam" reports will probably not be taken on their own, but will be considered along with other information, analysis of the message, etc. Because different users have different needs and different views of what constitutes spam, reports from one user might or might not be applicable to others. And because users might sometimes press a "report not spam" button accidentally, immediate strong action, such as marking all similar messages as "good" based on a single report, is probably not the right approach. Recipients of "not-spam" reports need to consider what's right in their environments. There are anti-spam systems that use "not spam" feedback today. All of them take the reports and mix them with other spam reports and other data, using their own algorithms, to determine appropriate Li & Leiba Expires January 3, 2012 [Page 3] Internet-Draft Email Feedback Type: not-spam July 2011 action. In no case do the existing systems use a "not spam" report as an immediate, automatic override. 1.2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. These terms take their normative values only when presented in UPPER CASE. 2. Feedback Report Type: Not-Spam This document only defines a new feedback report type, "not-spam", extending the Email Feedback Reports specification [RFC5965]. In the first MIME part of the feedback report message, the end user or the mail client MAY add information to indicate why the message is not spam -- for example, because the originator or its domain is well known. 3. Example In the example, Joe, a pharmaceuticals sales representative, has received a message about discount pharmaceuticals. Because that is a frequent subject of spam email, the message has been marked as spam -- incorrectly, in this case. Joe has reported it as "not-spam", and this is an example of the report. Note that the message is DKIM-signed [I-D.ietf-dkim-rfc4871bis], a good security practice as suggested in RFC 5965 section 8.2 [RFC5965]. DKIM-Signature: v=1; a=rsa-sha256; s=abuse; d=example.com; c=simple/simple; q=dns/txt; i=abusedesk@example.com; h=From:Date:Subject:To:Message-ID:MIME-Version:Content-Type; bh=iF4dMNYs/KepE0HuwfukJCDyjkduUzZFiaHqO9DMIPU=; b=e+BF8DCHFGqCp7/pExleNz7pVaLEoT+uWj/8H9DoZpxFI1vNnCTDu14w5v ze4mqJkldudVI0JspsYHTYeomhPklCV4F95GfwpM5W+ziUOv7AySTfygPW EerczqZwAK88//oaYCFXq3XV9T/z+zlLp3rrirKGmCMCPPcbdSGv/Eg= From: Date: Thu, 8 Mar 2005 17:40:36 EDT Subject: FW: Discount on pharmaceuticals To: Message-ID: <20030712040037.46341.5F8J@example.com> MIME-Version: 1.0 Li & Leiba Expires January 3, 2012 [Page 4] Internet-Draft Email Feedback Type: not-spam July 2011 Content-Type: multipart/report; report-type=feedback-report; boundary="part1_13d.2e68ed54_boundary" --part1_13d.2e68ed54_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit This is an email abuse report for an email message received from IP 192.0.2.1 on Thu, 8 Mar 2005 14:00:00 EDT. For more information about this format please see http://www.mipassoc.org/arf/. --part1_13d.2e68ed54_boundary Content-Type: message/feedback-report Feedback-Type: not-spam User-Agent: SomeGenerator/1.0 Version: 1 --part1_13d.2e68ed54_boundary Content-Type: message/rfc822 Content-Disposition: inline Received: from mailserver.example.net (mailserver.example.net [192.0.2.1]) by example.com with ESMTP id M63d4137594e46; Thu, 08 Mar 2005 14:00:00 -0400 From: To: Subject: Discount on pharmaceuticals MIME-Version: 1.0 Content-type: text/plain Message-ID: 8787KJKJ3K4J3K4J3K4J3.mail@example.net Date: Thu, 02 Sep 2004 12:31:03 -0500 Hi, Joe. I got a lead on a source for discounts on pharmaceuticals, and I thought you might be interested. [...etc...] --part1_13d.2e68ed54_boundary-- Example 1: Not-spam report 4. Security Considerations All of the Security Considerations from the Email Feedback Reports specification [RFC5965] are inherited here. Li & Leiba Expires January 3, 2012 [Page 5] Internet-Draft Email Feedback Type: not-spam July 2011 Not-spam reports could possibly be used in an attack on a filtering system, reporting true spam as "not-spam". Even in absence of malice, some not-spam reports might be made in error, or will only apply to the user sending the report. Operators need to be careful in trusting such reports, beyond their applicability to the specific user in question. 5. IANA Considerations Registration is requested for the newly defined feedback type name: "not-spam", according to the instructions in section 7.3 of the base specification [RFC5965]. Please add the following to the "Feedback Report Type Values" registry: Feedback Type Name: not-spam Description: Indicates that a message is not spam. This may be used to correct a message that was incorrectly tagged or categorized as spam. Published in: this document Status: current 6. Acknowledgements The authors would like thank Murray S. Kucherawy and Bert Greevenbosch for their discussion and review, and J.D. Falk for suggesting some explanatory text. 7. References 7.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5965] Shafranovich, Y., Levine, J., and M. Kucherawy, "An Extensible Format for Email Feedback Reports", RFC 5965, August 2010. 7.2. Informative References [I-D.ietf-dkim-rfc4871bis] Crocker, D., Hansen, T., and M. Kucherawy, "DomainKeys Identified Mail (DKIM) Signatures", draft-ietf-dkim-rfc4871bis-13 (work in progress), Li & Leiba Expires January 3, 2012 [Page 6] Internet-Draft Email Feedback Type: not-spam July 2011 June 2011. [OMA-SpamRep-RD] Open Mobile Alliance, "Mobile Spam Reporting Requirements", OMA-RD-SpamRep-V1_0 20101123-C, November 2010. Authors' Addresses Kepeng Li Huawei Technologies Huawei Base, Bantian, Longgang District Shenzhen, Guangdong 518129 P. R. China Phone: +86-755-28974289 Email: likepeng@huawei.com Barry Leiba Huawei Technologies Phone: +1 646 827 0648 Email: barryleiba@computer.org URI: http://internetmessagingtechnology.org/ Li & Leiba Expires January 3, 2012 [Page 7]