Many IPSs offer bulk mailers as a service in order to provide automated feedback messages on address data, so-called feedback loops, a mechanism that is made available by the mailbox provider to deliver information about spam complaints that occurred after an email campaign to e-marketers.
If a company or sender signs up for a feedback loop (FBL), they always receive a notification from the mailbox provider in case a complaint is lodged to the ISP after an email campaign. Thus, the FBL primarily serves the purpose to take receivers out of the distribution list which complain.
Feedback loops are not offered by all mailbox providers, but to name at least some of the important ones, for instance, AOL; Excite, Comcast, Hotmail, Mail.ru; Yahoo!; or Zoho.com, to name a few.
How to register for a feedback loop as an email sender
To arrange a feedback loop with a mailbox provider, in general the sender must complete a registration process. The application can usually be initiated through the postmaster site of the mailbox provider and, depending on the provider, require different information for the registration process. However, key elements usually include contact information, IP address(es) and a dedicated email address to receive the feedback regarding complaint information, which must be set up by the sender. It makes sense to use this address for a so-called parsing script that is needed for a syntactic analysis that combs through incoming emails.
In fact, the information returned to the sender in the feedback loop only consists of a copy of the originally sent email to the recipient that lodged a complaint. The most common used program, used by mailbox provider, is the so-called "Abuse Reporting Format" (ARF). From the returned complaint emails, the sender can now take the required information from each email header and content. This should be at least the email address of the addressee, so that it can be immediately removed from the mailing list. However, there are mailbox providers that make the email addresses of users who complain unrecognizable before the offending email gets back to the sender by FBL. Then the e-marketers must use other ways to locate the respective email addresses, such as e.g. through special links in the message itself or subscriber identifiers in the X-header.
What are the benefits of FBLs?
Removal of addresses complaining of spam from the distribution list: The main purpose of the feedback loop process is identifying and taking complaining users’ email addresses off the mailing list to avoid more trouble and to prevent being labeled as spammer. We all know that a high number of complaints usually triggers further blocking of emails or sending of more messages directly to the spam folder instead of delivering them properly to the Inbox of the recipient.
Identification of compromised hosts: The safety of the own brand and the company's own IP range in the network should not be taken lightly. FBLs help uncover potential security problems because they show incoming complaints from the entire IP range of the sender. If your IPs have been compromised, you could, for instance, receive complaints about emails you have never sent.
Identifying problematic campaigns/acquisition methods: E-marketers and senders can get further information from feedback loops, such as the campaign ID or the address source. Both such information from be retrieved from the email header that allows detecting which campaigns are causing the most problems or initiated spam complaints. Then you can take factors such as the content and frequency under the microscope and might come across a particular source that causes many ailments. In such a case the sending could get outsourced to a different IP address, not to interfere with the rest of the email program and its deliverability.
By Daniela La Marca