What is a spamtrap and why do they matter?

Quick points:

*Spamtraps are addresses owned by antispam organizations
*Emailing a spamtrap (usually) gets your IP or domain blocklisted
*Maintain current, direct opt-in with an active lead database to avoid this

What is a spam trap or spamtrap?


A spam trap, or spamtrap is an email address secretly owned by an antispam organization that is used to detect spam. Antispam organizations do not sign up for mailing lists, so they consider any email sent to these addresses to be spam. Once email is sent to the spamtrap, the antispam organization that owns this address will blocklist the IP that sent the email (or, less often, domains that are linked in the message).


Email administrators purchase subscriptions to various blacklists, and use the lists to block all incoming email from listed IPs or containing listed domains. From the marketer’s perspective, this can mean a high number of bounced emails leading to low lead engagement, and ultimately to weak revenue performance.


There are two types of spamtraps – pristine traps, and repurposed/recycled traps. A pristine trap is an email address that was never used by a person. A repurposed trap is an email address that once belonged to someone but is no longer a valid address; these addresses will bounce as bad addresses for at least six months before an antispam organization will turn them into live traps.


How can a spamtrap get into my Marketo lead database?

Purchased data


Purchased data is unreliable. The antispam world does not like the use of purchased data so antispam administrators have made a concerted effort to get spamtrap addresses into the databases of data vendors. While data vendors may say they provide opt-in data in reality consent should be direct to your company.

Sending unsolicited email is prohibited by the Marketo Terms of Use because this practice has a high risk of causing blocklist issues that can destroy deliverability for multiple Marketo customers. To avoid spam traps get direct opt-in before sending email.

If you have purchased data in the past we recommend setting any inactive purchased leads to marketing suspended or simply removing them from your database.

Old data

Repurposed traps are email addresses that were once valid but are now owned by an antispam organization. This can happen when a company goes out of business; expired domains are often purchased by antispam organizations. Sometimes a company that has a direct partnership with an antispam organization will allow email addresses of former employees or users to become spamtraps.

Because antispam organizations will generally make sure future spam traps return a bounce as bad addresses for at least six months before they become spam traps you can prevent repurposed traps in your database by emailing remaining engaged with everyone in your database at least once every six months.

Avoid “wake the dead” campaigns to addresses you have not contacted in more than six months.

Unconfirmed form entries

People can unintentionally enter spamtrap addresses into forms either by making a typo or by intentionally using a fake email address that happens to be a spamtrap. If you use single opt-in, you may add spamtraps to your mailing list. This is more likely to happen if you are a B2C company or if someone thinks they can get whitepapers or free trials simply by filling out a form with made-up information.


How can I identify spamtrap addresses?


Spamtrap addresses are considered trade secrets by the antispam organizations. They do not share these addresses because their goal is for senders to change their mailing practices rather than to simply remove spamtraps from their mailing lists.


That said, one thing we do know about spamtraps is that they tend to be automated processes and do not engage. Spamtraps do not click links. You can use smart list filters to identify inactive leads in Marketo.


How can I prevent spamtraps in my database?

  • Maintain active, direct opt-in for all leads.
  • Don’t purchase data (to grow your list, sponsor events, use list rental services that send the first message for you, or use co-branded content that sends you only good leads)
  • Email everyone you want to email at least once every six months
  • Don’t add old data directly to your mailing list (if you need to, add in small batches and send a welcome email with a slightly different subject to each batch)
  • Regularly clean your database of inactive leads
  • Grant access to assets such as free trials and whitepapers as email links to discourage intentional use of fake email addresses on forms
  • Use scripting on your forms to identify potential typos

Is this article helpful ?



Labels (1)