In the constant struggle between ISPs and spammers, legitimate marketers get caught up somewhere in the middle. ISPs have an array of techniques and technologies they employ to keep out spammers and to determine legitimate senders of email, and one such technique is the spam trap or honey pot.
By definition, a spam trap is an email address maintained by an ISP or third party, which neither clicks nor opens emails, meaning it does not actively engage with the emails it receives.
Marketers need to be aware of two types of spam traps:
Spam traps exist as a way of determining if you are marketing to recipients who have opted in to receive your emails, remove / suppress bounced emails and are mailing to recipients who engage with your emails.
Let's examine 2 popular types of spam traps:
Hotmail spam traps are usually old email addresses which have since been abandoned. Here is a scenario:
John registered to receive your newsletters a year ago. Since then, he has decided not to use his account anymore and has not logged in. After a few months, his account is deactivated, but still receives emails.
After a few more months of no user activity by John, Hotmail closes John's account and he will no longer be able to re-activate or log in. Any emails sent after the account is closed will bounce and it is during this time that marketers who follow best practices should be removing addresses like John's.
A few months later, Hotmail will reactivate John's email address as a spam trap, but this time the email account will accept emails without a bounce notification. The account however will not click or open emails, and Hotmail will use this address to determine if you are mailing to active, and engaged recipients or not.
The number of these spam traps marketers send to, become a metric Hotmail monitors alongside bounces, complaint rates, etc.
To quote Spamhaus:
"The Spamhaus Project is an international non-profit organization whose mission is to track the Internet's spam operations and sources, to provide dependable real time anti-spam protection for Internet networks, to work with Law Enforcement Agencies to identify and pursue spam gangs worldwide, and to lobby governments for effective anti-spam legislation."
Spamhaus defines spam traps as an email address that is used to capture spam sent to it, in order to provide information on what spam is being sent and where it originates from. These honey pot email addresses do not belong to real users and are decoys setup to monitor, collect and catch spammers.
Once you are caught mailing to these spam trap addresses, your IP address is listed on the Spamhaus blacklist database. Several companies and large ISPs such as Hotmail, Yahoo and AOL consult the Spamhaus spam-blocking database when filtering their email, and then may choose to block emails until the listing is removed. This obviously can be detrimental to your deliverability and to your brand, and that's usually when concerns arise such as:
These are all great questions. I have examined strategies to identify and remove spam traps, and ways to avoid being caught by them in How to Protect Your List from Spam Traps.
Read Email Deliverability: Guide for Modern Marketers to find out how to achieve email deliverability that really delivers.