The Abuse Reporting Format (ARF) is the standard format used by mailbox providers to provide generic spam reports when submitting abuse complaints to other mailbox providers, email service providers, bulk mailers, and subscribers to feedback loop (FBL) services.
Here is a sample ARF message:
From: <abusedesk@example.com>
Date: Thu, 8 Mar 2005 17:40:36 EDT
Subject: FW: Earn money
To: <abuse@example.net>
MIME-Version: 1.0
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