Spam Traps are one way of identifying and monitoring spam. Creating them is as easy as taking an email address that hasn’t been subscribed to any emails, and sending an email to it. Since they haven’t subscribed to any mail, these messages will be considered spam. This guide will explain how spam traps work, and best practices for avoiding them.
Overview
There are a wide variety of spam traps. Sources for spam traps are usually old addresses that were used as role addresses in domain registrations (sales@ info@ support@), or email addresses that were once valid but have been reassigned for trapping spam.
Usually, this type of spam trap has once opted in to receive email, and was likely published on a page somewhere online. This is not that case for dictionary attackers, since they generate randomized addresses at common domains (i.e. example1@example.com, example2@example.com, and so on).
Why do you need to avoid spam traps?
Spam traps are important because so many large ISP, spam filter provider, and Domain Name System block lists use them. Sending an email to a spam trap can directly lead to being blocked by the organization that set up the trap. Blocking can damage a business’s reputation, and halt further email deliverability.
Best practices for avoiding spam traps
We recommend the following best practices for avoiding spam traps and blocking:
Avoid bad email list sources: This includes any list comprised of email addresses that have not opted in to receiving your messages. There’s a good chance that a spam trap is included in this type of list, and furthermore, you shouldn't be sending unsolicited messages. Avoiding unsolicited lists will help ensure your business’s reputability.
List contamination: List contamination is when an email address that is a spam trap was added deliberately or accidentally to an unconfirmed list. (This is a list with single opt-in or notified opt-in) To avoid list contamination, make sure to check the correct spelling of the list’s email addresses, and take advantage of double opt-in for every list. For more information, see Double opt-in (SendGrid Blog).
List age: Like previously mentioned, spam traps are sometimes sourced in outdated email addresses that are no longer valid. Going for long periods of time (over one year) without sending mail to an address can lead to getting caught in a spam trap. To prevent this type of spam trap, we recommend cleaning out your email lists at regular intervals. For more information, see Managing your lists (SendGrid Docs).
How to remove spam traps from email lists
Removing a spam trap can be difficult and time consuming. However, it is inefficient and expensive to throw out an entire list. We recommend users practice thorough and routine list maintenance to help avoid these issues.
One method for helping to maintain your email lists is to employ list segmentation. For more information, see The Essential Guide to Email Segmentation (SendGrid.com).