What information do FBL reports contain?

An FBL report is a structured complaint email. It tells you what happened, who reported it, and which of your messages triggered it. The format is the Abuse Reporting Format (ARF), specified in RFC 5965, and most providers stick to it.

What's in a typical report

• Feedback type. Almost always abuse, meaning the recipient marked your message as spam.
• Complainant address. The recipient who clicked the spam button. Some providers (Outlook JMRP) send the address in the clear. Others hash or anonymize it. Even hashed, your ESP can usually match it back to your subscriber if the hash is consistent.
• Original message headers. The full headers of the email that got flagged. SPF, DKIM, DMARC results, the Message-ID, the From and Return-Path, the timestamps. This is how you prove which send triggered the report.
• Complaint timestamp. When the recipient clicked "Spam," not when you sent the message.
• Sometimes the message body. Some providers include it so you can see exactly which campaign content was reported. Some strip it for privacy. ARF includes a separate part for it if present.
• Reporting MTA / source. Which provider generated the report. Useful when you're enrolled with several.

What's not in a report

You don't get the recipient's reason. There's no comment field. You don't get a way to contact them. You don't see whether they unsubscribed first or went straight to "Spam" (though you can infer from your own logs).

What to do with it

1. Suppress the complainant immediately and forever. Never email them again, even if they re-subscribe through a form. They've signaled they don't want your mail.
2. Pull the original Message-ID out of the headers and trace it back to the campaign. Cluster complaints by campaign, list segment, and acquisition source.
3. If a single source (a paid lead form, a co-marketing partner, an old import) accounts for most complaints, that's where to fix the program.

If your ESP doesn't surface this analysis well, Review My Emails can pull the patterns out of your complaint data so you're not eyeballing ARF files by hand.