Feedbackloop
Complaint Feedback Loops are feedback in form of ARF reports, usually sent by E-Mail to a previously registered address. Feedbackloops are sent by ISP's to senders when mail from the sender in question has been marked as SPAM. Some feedbackloops are registered by IP, meaning a complaint report is sent when a mail from a certain IP is marked SPAM, and others by domain, meaning a complaint report is sent when a mail from a certain domain is marked SPAM.
Complaint Feedback Loops have two functionalities:
- To detect IPs, domains and brands that are sending unwanted E-Mail.
- To unsubscribe recipients that have marked message(s) as SPAM.
List of free and independent feedbackloops
Directly from the ISP
The following list of Feedbackloops is facilitated directly by the ISP receiving the SPAM complaint. If, for example, the earthlink FBL is registered, only Earthlink ARF Reports will be received.
| Name | Registration Link | IP/Domain based | Note |
|---|---|---|---|
| 1&1 | Register via the Postmaster page. | IP | Only for mail.com, web.de and various gmx domains. |
| Earthlink | fblrequest@abuse.earthlink.net | IP | E-Mail registration. Send it from the address that's to be registered and don't forget to mention your IPs! |
| Google Postmaster | https://gmail.com/postmaster/ | IP/Domain | No E-Mail reports. |
| mail.ru | https://postmaster.mail.ru/ | Domain | Read https://help.mail.ru/enpostmaster/technical-settings/fbl. |
| Microsoft | https://postmaster.live.com/snds/JMRP.aspx | IP | E-Mail reports are not in ARF. |
| Yahoo | https://senders.yahooinc.com/contact | Domain |
Provider independent
Provider independent FBLs are facilitated by independent third parties.
| Name | Registration Link | IP/Domain based | Note |
|---|---|---|---|
| Abusix | Add a CFBL header to outgoing E-Mail | IP | XARF reports. Will be available soon. |
| SpamCop | https://www.spamcop.net/anonsignup.shtml | IP | IPs from Mail reported to SpamCop are added to the SpamCop blacklist |
Paid Feedbackloop subscriptions
In addition to the above list, it's possible to register for a list of collective Feedbackloops from various small ISPs via Validity's Feedbackloop Service (fbl.validity.com). It used to be a free service, but since September 2023, receiving ARF reports via E-mail via this service costs $1.500 per year. The service covers the following ISPs:
- Bluetie
- Comcast
- Fastmail
- gandi.net
- LaPoste.net
- Libero (Italiaonline)
- Liberty Global (Chello, UPC, and UnityMedia)
- Locaweb
- OpenSRS/Hostedmail (Tucows)
- Rackspace
- Seznam
- SFR
- SilverSky
- Swisscom
- Synacor
- Telecom Italia
- Telenet
- Telenor
- Telstra
- Terra
- UOL
- Virgilio
- Virgin Media
- Yandex
- Ziggo
Standardisation
In May 2023, work on standardisation of registration to Complaint Feedback Loops via Complaint Feedback Loop Address Headers was started. In September 2023, RFC 9477 was accepted in "experimental" status. Implementation of this new standard would obsolete all paid or otherwise complicated feedbackloops, providing a standardised, open and free subscription mechanism.