Email List Hygiene

Spam Traps: What They Are and How to Avoid Them

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Spam traps are email addresses with the sole function of identifying and catching, well, spammers. Unfortunately, anyone can fall victim to a spam trap if they aren’t careful about contact list hygiene, opening them up to a slew of potential problems. 

The best defense in your arsenal is to keep up with email best practices. But first, here’s everything you need to know about spam traps (and more importantly, how to avoid them).

What is a spam trap?

While spam trap emails could have been valid at one point in time, they aren’t anymore. Maybe this email address is old enough to have been reclaimed by the issuing mailbox provider (MBP), or the email’s domain was wrongly submitted upon sign-up. Maybe that email cannot receive mail, was built to be scraped, or some combination thereof. 

Regardless of their origin, Internet Service Providers (ISPs) and other spam-blocking agents are constantly on the lookout for these mailbox menaces.

How serious is a spam trap for my business?

As any thriving business owner knows, a good email list is a crucial part of successful marketing. However, practicing poor list hygiene can quickly put your business on a rocky domain (excuse the pun).

Because Internet Service Providers and blocklist (also known as blacklist) operators use spam trap email addresses to identify bad actors, getting caught in one can have serious consequences.

Consequences like:

  • Domains or IP addresses being blocklisted 
  • Emails being automatically sent to the spam folder
  • Damage to a sender’s reputation with mailbox providers

What are the types of spam traps?

As is true of email deliverability, spam traps are multifaceted––not all are created equally. That’s why, to fully understand their impact, you must first understand what kinds of spam traps live in the email world and why.

At the highest level, spam trap emails can be broken into three categories: typo, recycled, and pristine

Typo traps

Typically, a typo spam trap is an address that’s been incorrectly entered upon sign-up. Common errors include adding too many of a certain letter (e.g., [email protected]) or missing characters. Fun fact: (meant to be is one of the most popularly misspelled domains. Sorry, Gail.

Typo spam traps can be weeded out easily enough using an email address verification solution at the time of collection. You could also implement a drop-down on the sign-up form with common domain options. When [email protected] begins typing too many o’s, a pre-populated “did you mean…” drop-down can be made to appear with options like,,, etc. 

This allows a user to correct their mistake before clicking submit. Some typo traps can be caught and removed through the use of a validation tool after the fact, and it’s not a bad idea for email marketers to have an in-house list of common typo domains to verify against. Typo-laden addresses can also be removed through confirmed opt-in and engagement-based sunsetting strategies.

Recycled traps

Also known as “honeypots,” recycled spam traps are invalid emails that were, at one time or another, live addresses. This address has now been reclaimed by the mailbox provider due to inactivity. 

For instance, do you remember your very first email address? No need to say it out loud. If you haven’t used it since the last time you heard AOL chime, “You’ve got mail,” it likely qualifies as a recycled trap. General practice mandates email addresses must be inactive for a minimum of 12 months to qualify as recycled spam traps.

For email marketers, recycled spam traps often surface when there is older data lingering on a sender’s list. List decay and recycled traps become most apparent when sending certain re-engagement campaigns or legally required notifications when an older or entire email list must receive a campaign. Recycled spam traps can also crop up when using third-party lists, because the sender likely doesn’t know the origins of the opt-ins.

Like typo traps, recycled spam traps are a natural part of the email ecosystem. Addresses get abandoned; people change companies and/or names (and subsequently, want an email that matches). It’s best for your sender reputation to find and remove as many of these invalid addresses as possible.

Pristine traps

A pristine trap is a fake email address that was never meant to be on a sender’s list. These addresses are created solely to be used as traps, then left in the wild to be scraped from websites, purchased, and passed around. Sometimes, they aren’t even set up to receive mail. For these reasons, pristine spam traps are the most dangerous for senders looking to maintain a good reputation.

Pristine spam traps are most commonly hit by senders emailing purchased lists, as there is little to no way to verify the integrity of the data purchased. It’s important to note that these addresses will never actually sign up to receive mail (so there won’t be any record of consent). Pristine spam traps are also exceedingly hard to identify, so if you can’t prove certain subscribers explicitly consented to join your email program, don’t email those addresses.

What is the difference between a spam trap and spam filter?

Spam filters are designed to automatically identify and block unwanted emails, whereas spam traps are email addresses specifically created to catch spam.

Email providers and anti-spam organizations use spam traps to monitor and track sources of spam, helping to improve the accuracy and effectiveness of spam filters in detecting and blocking unsolicited messages.

Together, spam filters and spam traps work in tandem to mitigate the impact of spam on email users.

How to identify a spam trap

Once you’ve gained a thorough understanding of the what and why of avoiding spam traps, you’ll naturally be interested in the how. Short answer: track your email engagement. If you’re experiencing unexpected dips in clicks, opens, or conversions, or an increase in bounce rates, spam traps may be the culprit.

Spam trap addresses don’t belong to real subscribers, so they won’t click, open, or engage with any of your emails. Senders can also weed out spam traps by regularly assessing the quality of their lists, and using the following best practices:

Check if your IP address or domain is list-denied

Being blocklisted by domain blocklisting services, Internet Service Providers, or spam-blocking agencies is a natural consequence of having spam trap email addresses in one’s contact list. Sender score can check your email or IP address to see if you have been added to any blocklists. 

There are several popular sites to check for IP addresses or domains that have been list-denied, so doing a quick search is always prudent.

Check delivery rates

If you’re noticing your delivery rates going down, you’re likely trying (and failing) to send to inactive or invalid email addresses, including spam traps.

But remember: Delivered rate only measures the percentage of email that was accepted or rejected by a mailbox provider (MBP). The delivered rate doesn’t disclose whether accepted messages land in the inbox or the spam folder.

For a better way to monitor spam placement and detect spam traps, senders should track their inbox placement rate. Inbox placement rate represents the percentage of emails delivered to the inbox, versus messages sent to the spam folder, rejected, or blocked. 

Check sender reputation

Sender or domain reputation is a key component of your email deliverability. Mailbox providers use it to decide whether or not your emails make it into subscribers’ inboxes. A poor reputation makes it far more likely that your emails will go straight to spam land.

For example, Microsoft’s Smart Network Data Services (SNDS) is a free service that offers important insight into sender reputation and email deliverability with Microsoft mailboxes. Senders can also check their Sender Score, a numerical representation of their sender reputation.

Put simply, doing regular audits and pulse checks help you identify and remove spam traps before they have time to do much damage.

How to avoid spam traps

That said, having a proactive approach to collecting and verifying contact emails is a surefire way of keeping you protected against the Big Bad Blocklist. Follow these best practices to keep your list clean and full of subscribers who actually want to hear from you.

Never purchase email lists

Arguably the best way to avoid spam traps altogether is to avoid purchasing email lists. It’s far too risky. For one, there’s no way for you to know the validity of those addresses or whether they’ve even opted in to receive your emails. Plus, the recipients on the list hold no real connection to your brand, making it an easy choice for them to mark your emails as spam. Most importantly, evolving privacy laws like GDPR make it illegal to contact people who haven’t provided their explicit consent.

Clean and validate your data

Regular list cleaning should help you catch typos and recycled traps before they threaten your performance. The best option is to use a software platform to validate the email addresses on your list, as manual audits are typically time-consuming and prone to error. 

Remove inactive subscribers

Make it a habit to keep a close eye on your engagement rates, especially hard bounces and clicks, to identify and remove inactive subscribers who might become recycled traps.

Another option is to send re-engagement campaigns to subscribers who have been inactive for a long time. If this latest campaign doesn’t hook them, sunset them as subscribers.

Use double opt-in for email

As mentioned above, real-time validation allows senders to confirm that addresses on their list are real accounts. This helps you avoid incorrectly spelled addresses making their way into your list. Double opt-in methods take this a step further by sending a post-sign-up email for subscribers to unequivocally opt to receive your emails.

Final thoughts

Spam traps may be inevitable, but they’ll only be a scourge on your sender reputation if you let them. Staying vigilant and practicing good list hygiene is crucial to any business sending email.

That said, the best way to identify and remove traps (and keep your domain reputation in good standing) is to:

  1. Avoid purchasing email lists
  2. Conduct regular list audits
  3. Require double opt-in when subscribers sign up for your email program

If you can do the above, you’ll have much more time to focus on upping your email game in other ways. Looking for more tips? For expert guidance to reach the next level of email performance, download the Ultimate Email Marketing Toolkit.