*Updated in September 2024
What is a feedback loop (FBL)?
An FBL is an arrangement between an email sender, such as Marketo, and an Internet Service Providers (ISPs) or email hosting service. The FBL allows the email sender to be automatically notified when the user who receives an email marks it as spam.
When a lead who uses one of these ISPs clicks the spam button for an email, the ISP sends an automated notice to Marketo. Marketo automatically unsubscribes the lead with the unsubscribe cause, "Customer Complaint Received from ISP". Marketo's Email Compliance Team also logs these complaints for internal compliance monitoring.
What FBLs is Marketo enrolled in?
By default, all emails sent by Marketo are covered by an FBL with the following email providers:
- Bluetie/Excite
- Comcast
- Fastmail
- Gandi.net
- Italiaonline
- Lapost.net
- Liberomail
- Liberty Global
- Locaweb
- Mail.ru*
- QQ.com*
- OpenSRS/Tucows
- Rackspace
- Seznam.cz
- SFR
- SilverSky
- Swisscom
- Synacor
- Telenet
- Telenor
- Telstra
- Terra
- TIM
- Unitymedia
- UPC
- United Online/Juno/Netzero
- Virgilio
- Virgin
- Yahoo!
- Ziggo
- Zoho.com
*The FBLs for Mail.ru and QQ.com can only be set up for customers on dedicated IPs. Please reach out to Support if these Russian and Chinese ISPs respectively are targets for your email program.
Notably, Gmail does not offer a traditional FBL. They have a similar offering that Marketo has evaluated and determined does not meet the needs of our clients at this time. Google does offer Postmaster Tools that allow senders to monitor their complaint rate and other reputation information. Senders can sign up here: https://gmail.com/postmaster/
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