"Feedback Loop" is a term used to describe any process in a system that uses the outcome of a situation as future input.
If we are to apply this concept to email, then basically a feedback loop is any feature or mechanism that provides information about the outcome of an email with which we use for future delivery.
Tracking opens or clicks, for example, can be part of a feedback loop. An email is sent, the recipient opens the email, this data is transmitted back to the sender, and the sender uses this data for future sends. You will often see "Feedback Loops" referred to as "FBLs". However, right now, the terms "FBLs" & "Feedback Loops" in the email industry have been monopolized by ISPs to refer to the features they use to notify senders of complaints specifically.
What is a complaint
The first question you might have is "What is a complaint?". A complaint is whenever a recipient receives an email to their Inbox and they intentionally mark the email as Spam or Junk.
In most email clients this will move the email from the Inbox to the Spam/Junk folder and in most cases will cause any future emails from the same sender or of similar content to be put into the Spam/Junk folder as well. This is very different from deleting an email.
By marking an email as Spam or Junk the recipient is telling their Internet Service Provider or Email Server that the email is unsolicited.
Are IP addresses used as identifiers?
Email is sent via an IP address. An IP address is a numerical identifier assigned to each device that accesses the internet.
When an email is sent, it is sent via the IP address of the device. It can get more complicated than that, but the important thing to know is that IP addresses are used in part to identify the sender.
Most email providers such as Yahoo, Hotmail, Gmail, & AOL offer senders the ability to register their IP address that is used to send an email. That way, if a recipient marks any email as Spam, the ISP can forward a notification of this action to the sender. This is known as an "Abuse Report" or "Complaint". Email etiquette then demands that the sender blocks any future emails to the recipient who complained, or remove the recipient address completely from their list.
This is the process by which senders receive notifications of recipients who are marking their emails as Spam or Junk and In the email, when you hear the term "Feedback Loops" this is the process that it is most likely referring to.
Do I have to set up Feedback loops?
No. Elastic Email takes care of this whole process for you. When you use Elastic Email, all emails are sent via our servers and IP addresses and we have already registered our IPs with most provider's feedback loops.
If you send an email via our service, and the recipient marks the email as Spam or Junk then that email will have a status of "Complaint" in your Elastic Email account. Any contact that receives a complaint will also be changed to a status of "Complaint" and will be blocked from receiving any future emails via the Elastic Email service.
Elastic Email closely monitors the rate of complaints for our senders.
The industry standard for acceptable complaint rates is 0.1%. However, even a single complaint is something you should investigate as it can be a sign that you need to improve or change your list management practices. All efforts should be taken to ensure your recipients are positively engaging with your emails. Our blog and help documentation is full of information on the best ways to do that.
Contact support if you've got questions!