A spam trap is an email address that is used to identify and monitor spam email. It is also a type of honeypot because it uses a fake email address to bait spammers. Internet service providers (ISPs), antispam organizations, blocklist providers and corporations use spam traps to monitor and reduce the amount of spam traffic to their networks.
A spam trap uses filters to block certain email addresses that have a history of sending spam. The spam trap analyzes all or part of the email address to identify it and decides whether or not to mark it as a spam-sending address.
Despite their objective of blocking spam email addresses, spam traps can unintentionally block legitimate, nonspam email addresses as well, which can damage the sender's reputation and email deliverability. Spam traps can cause the sender's domain list or Internet Protocol (IP) address to be denied.
There are several types of spam traps, and they all work a little differently.
Pure spam traps. Also known as pristine spam traps, these are email addresses created by ISPs and other organizations that have never been associated with a real person. These email addresses only exist to function as a spam trap. The email addresses are embedded into websites so that, when spammers scrape the sites to add to their mailing list of spam targets, they unknowingly pick up the trap as well. The administrator of the spam trap then watches to see which addresses email the trap. Those that email the trap are deemed to be spam and are blocked, or are more closely monitored, as they harvested that contact -- the trap's address -- in a suspicious manner, as opposed to asking for the address as a legitimate sender would do. A pure spam trap will damage the sender's reputation if an antispam organization finds it in the sender's contact email list.
Recycled spam traps. These are often email addresses and domains that were at one time legitimate but have since been repurposed as spam trap addresses. Some common examples of repurposed addresses are role addresses, which might look like the following:
Email addresses of employees who no longer work for a company can also be used as recycled spam traps. The address still exists, but it is no longer used for its intended purpose. So, it gets recycled as a spam trap. The recycled spam trap is generally not as harmful to senders as the pure trap but still can cause damage over time. Unlike addresses designed specifically for trapping spam, recycled addresses have an element of legitimacy. They are more likely to attract legitimate traffic -- for example, those who previously corresponded with the owner of the address before it was recycled.
Typo spam traps. These are spam traps that, like recycled traps, aim to look legitimate. However, instead of recycling a legitimate address, they contain subtle typos, even though they are a different address. Examples include the following:
Like recycled spam traps, these will not damage a sender's reputation as severely as pure traps but will signal antispam authorities over time.
A spam trap has features that a normal user would typically notice and, as a result, would cause the user to cease correspondence. These include the following:
To check if a spam trap is included in an email list, the sender of that list should check their email delivery rates. If delivery rates are dropping drastically, the sender's list may contain a spam trap. This is because spam traps do not respond to or conventionally read emails sent to them. Emails are sent to them but not registered as delivered. Also, the fact that the address does not respond damages a sender's reputation. There are tools senders can use to analyze their contact list for spam traps.
If senders believe they have a spam trap in their list, they can check to see if the email addresses are on an email blocklist. Some common IP or domain blocklists to check include the following:
Blocklist tool vendors maintain and add to their blocklists. For example, SpamCop adds IP addresses reported by its user lists. Senders who suspect they are on SpamCop's list can check that list, but it is difficult to get an address removed from one of these lists.
The best way to avoid acquiring spam traps in a contact list is to practice good email management. A poorly maintained email list could indicate a potential spammer and, therefore, attract a spam trap. A spam trap in the contact list will then worsen the sender's reputation by decreasing their email delivery rate.
Examples of sender behaviors that indicate poor email management include the following:
In order to avoid acquiring a spam trap, which would cause one to exhibit these bad sender behaviors, senders should follow email best practices. Some examples of email best practices include the following:
A cloud honeypot can help organizations gather threat intelligence. Learn more about the benefits and limitations of a cloud honeypot, as well as how to use a public cloud system to host a honeypot, here.
24 Feb 2021