Native Feedback Loop (FBL) / Spam Complaint Webhook Support

[adiux]

Hi everyone,

I’m currently looking into automated list hygiene and sender reputation management within Postal. While Postal does an amazing job of handling standard delivery, bounce, click, and open webhooks, I’ve noticed there isn't a native webhook event specifically dedicated to ISP Feedback Loops (FBL) or Spam Complaints.

Right now, when an ISP (like Yahoo or Microsoft) routes a spam complaint back via an ARF (Abuse Reporting Format) email, it requires building a completely standalone IMAP-polling parser or an external mail routing handler just to notify our main web application.

Proposed Feature:
It would be incredibly powerful if Postal could natively ingest and handle FBL emails.

Inbound FBL Parsing:
Postal acts as the destination for registered FBL emails (e.g., fbl@yourdomain.com).
Payload Extraction:
Postal reads the incoming ARF message, matches the headers or message ID back to the original message log, and flags it as a complaint.
New Webhook Event:
Trigger a MessageComplained or MessageSpamReported HTTP POST webhook payload containing the recipient and original message metadata.

Why this adds value:
Compliance & Deliverability:
Keeping spam complaint rates below Gmail and Yahoo's strict limits is critical for self-hosted mail servers. A native webhook allows backend apps to immediately unsubscribe users.

Unified Webhook System:
Developers wouldn't have to patch together custom Postfix scripts or third-party IMAP pollers just to catch spam reports.

Has anyone in the community successfully automated FBL handling natively within Postal, or is an official FBL webhook feature planned on the roadmap? I'd love to hear your thoughts or see if anyone is open to collaborating on a PR for this.

Thanks!

[willpower232]

Postal is mostly designed to just send emails, it doesn't have any concepts of lists etc.

It can handle incoming emails and direct them as a webhook amongst other things so you could integrate Postal within a more feature complete email list management program or add some kind of middleware as a separate program to convert the message into the appropriate webhook you are interested in.

[adiux]

Hi @willpower232 , thank you for your reply.

We can handle the lists on our end already, but I need to get the information. ATM we use Amazon SES/SNS. So we get a webhook similar to a bounce notification. I know Postal handles that already.

So with this feature, we would get a complaint in the same way as a bounce.

Here are some examples from Amazon:
https://docs.aws.amazon.com/ses/latest/dg/notification-examples.html#notification-examples-complaint