Feedback Loops

Feedback Loops List

This is the list of ISPs that have feedback loop programs and that we register to as part of the GreenArrow install process:

• Validity (Return-Path)
• Hotmail (SNDS and JMRP)
• Yahoo

Overview

A feedback loop is a mechanism for an ISP to forward spam complaints from its users to senders. The most common scenario in which a feedback loop complaint occurs is when a subscriber clicks the This Is Spam link, or its equivalent while viewing an email.

When this button is clicked at an ISP which you have a valid feedback loop registration in place with, the ISP sends a copy of the complaint to one of GreenArrow Engine’s Spam Complaint Mailboxes. Messages received at these mailboxes are processed by GreenArrow Engine’s Spam Complaint Processor, which extracts the recipient email address, ListID, and SendID from the message being complained about.

We recommend treating spam complaints as unsubscribe requests.

If the message was sent via GreenArrow Studio, then this is done for you.

If the message was sent from a different injecting application, then the Event Notification System can be used to log this complaint as an scomp event.

More details on Feedback Loops and Spam Complaints in general can be found on the GreenArrow Engine’s Spam Complaint Processor and Spam Complaint Mailboxes pages. The remainder of this document discussed specific feedback loops, and how to register for them.

Feedback Loop Registrations

Feedback loop registration requests are typically sent in 2 scenarios:

• When you’re adding new sending IP addresses, you would register each new IP for the IP Based feedback loops.
• When you’re adding in new signing DKIM key(s), you would register each new DKIM key for the DKIM based feedback loop.

GreenArrow technical support will send in feedback loop registration requests to the ISPs listed on this page as part of your server’s initial setup process. We can also send in subsequent registration requests for you, although there may be a fee involved. For more details, contact GreenArrow technical support with the IP address(es) and/or DKIM keys that you wish have registered.

IP Based Feedback Loops

Most feedback loops are registered for based on sending IP addresses. Once an IP address is registered with one of these feedback loops, any messages sent by that IP which generate a spam complaint will cause a feedback loop message to be sent.

Some IP based feedback loops require that the registration of the domain name that’s used in reverse DNS be at least 30 days old. Take this into consideration when selecting which domain to use in reverse DNS.

Registration requests for this type of feedback loop are typically authorized by looking up the reverse DNS, or PTR record associated with the IP address being registered, and sending a confirmation message to an abuse@ or postmaster@ address at the fully qualified domain name, or a parent domain. The confirmation addresses is selected during the registration process. The confirmation message contains a link which must be clicked to complete the registration.

Microsoft / Hotmail Feedback Loop and SNDS access

Hotmail’s feedback loop can be registered for here.

You first need to Request Access to the IP addresses to prove that you own the IP addresses.

After proving ownership, you can submit the Junk Mail Reporting Program request.

Validity

Validity’s Universal Feedback Loop Service processes feedback loops for more than 26 email providers.

You can choose to receive spam complaint at a different email addresses for each provider or use the same address for all of them. For simplicity, it is easier to use the same email address for all providers (ISPs).

DKIM Based Feedback Loops

DKIM based feedback loops are registered using DKIM keys configured in GreenArrow. Any message properly signed by a registered DKIM key will generate a complaint email when the recipient reports the message as spam.

Yahoo is currently the only provider that operates this kind of feedback loop.

Yahoo Feedback Loop

Go here to register your DKIM domains in Yahoo’s Sender Hub service, which also enables their Spam Complaint Feedback Loop service:

https://senders.yahooinc.com/complaint-feedback-loop/

To complete the registration, you will need to retrieve a verification code sent to the registered complaint email address. This email will be delivered to one of GreenArrow’s special mailboxes that cannot be accessed.

In order to retrieve the verification code, either:

(1) Configure the fbl_processor_forward_errors_to directive to forward the emails GreenArrow cannot process as a spam complaint.

(2) Run the following command to print a list of emails sent from Yahoo’s Sender Hub service that GreenArrow saved as files because they couldn’t be processed as a complaint:

grep -l "^From: [email protected]" /var/hvmail/maildata/Maildir-feedback/.INBOX.CouldNotProcess/new/*

The files printed by that command can safely be viewed using your preferred command line tool for viewing text files.

ISPs Not Offering Feedback Loops

Not all ISPs offer traditional feedback loops. The most notable case is Gmail:

Gmail

Gmail offers a feedback loop, but it only provides aggregate data. This means that you cannot use Gmail’s feedback loop to deactivate subscribers who generate spam complaints.

You can deactivate Gmail subscribers who mark a message as spam by including a List-Unsubscribe header. If you’re using a GreenArrow Studio installation that’s been updated since October 20, 2011, or GreenArrow’s SimpleMH, then this header is automatically included for you. Unsubscribes that take place based on the List-Unsubscribe header are logged as unsubscribe requests, rather than spam complaints.

abuse@ and postmaster@ Role Addresses

During the feedback loop application process, verification emails are sent to abuse@ or postmaster@ role addresses, which contain links that will need to be clicked.

If GreenArrow technical support is submitting feedback loop applications for you, you’ll be provided with a full list of addresses that these verifications emails will be sent to.

Most email hosting providers allow you to create abuse@ and postmaster@ role addresses. Google Apps is unique in that while they allow you to receive mail at these role addresses, the method that must be used to enable this is non-intuitive. The link below contains details on how abuse@ and postmaster@ role addresses can be configured for domains that have their email hosted by Google Apps:

https://support.google.com/a/answer/33389?hl=en

1. Log in to the control panel for the domain, and click on Groups
2. Click to create a new group
3. Set up the address with these settings
4. The new group with address will show up back on the groups page; click on it to add recipients
5. Add the recipients of the forwarder