Best practices

Spam Traps: What They Are and Why You Should Pay Attention to Them

EmailLabs Team, 29 May 2023


Spam Traps are email addresses used by ISPs, various spam-fighting organizations, and Blacklist administrators to identify and monitor the mailings of senders who do not follow good mailing practices when it comes to verifying their contact databases. The aim of their use is to reduce the amount of spam that reaches our mailboxes every day.

Global spam volume as percentage of total e-mail traffic from 2011 to 2022

There are many types of Spam Traps. Most of the time, Spam Traps are email addresses that have been inactive for a long. They can also be recycled email addresses that were once active but are no longer in use, or they can be newly created addresses that have never been used before. In all cases, however, a Spam Trap set up with the intention of catching senders who do not properly verify their contact lists.

If your mailing list contains these types of email addresses, it may mean you are not taking proper care of its hygiene. This can result in your messages being flagged as spam and your IP address being blacklisted. In the worst case, it can even lead to your email service provider shutting down your account.

Using EmailLabs, you can avoid falling into such a trap, as our system has a built-in Spam Trap address filter. When you send a message to an address on our internal, regularly updated list, the sending will be automatically blocked, and the message will receive a “dropped” status. It is important to note that our tool is not designed to clean old contact databases or to find Spam Trap addresses, so such addresses will not be marked in any additional way. To maintain the high deliverability of emails, always send them only to verified and up-to-date recipients.

That’s why it’s important to be aware of what spam traps are and how to avoid them.

Read on to learn more.

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Types of Spam Trap addresses

  • Pristine Spam Traps (PST) – These are new email addresses that have been created by ISPs or anti-spam organizations specifically to be Spam Trap emails – that is, addresses that have never been used before by regular email users (who might have consented to their processing). Such addresses are often posted on accessible, public websites. Spammers who extract data from them (web scraping) also unwittingly end up collecting these seeded email traps. Addresses gained this way (or, for example, illegally acquired in a data leak or hacking attack) are often sold on. The presence of pristine spam traps, therefore, helps to detect those senders who build their contact databases incorrectly, which can lead to the immediate blocking of their sending domain or IP address and significantly weaken the sender’s reputation.
  • Recycled Spam Traps (RST) – A recycled Spam Trap does not usually cause as much damage to senders as PST traps, but over time their presence can also lead to a weakened sender reputation and lower deliverability. Unlike email addresses specifically designed to catch spammers, recycled addresses have a certain element of legitimacy to them – they are very often contacts that were once valid addresses but have been abandoned (e.g. addresses of former employees, mailboxes of people who have moved to another vendor, addresses in expired domains, etc.). After a certain period of time (usually around 12-18 months), these are taken over and reactivated by the ISP and then converted into traps. They are more likely to attract regular, legitimate senders – for example, those who previously corresponded with its original owner before it was recycled. Such Spam Trap emails often appear in older groups of contacts, such as those you use for less frequent mailings – policy change or reactivation campaigns.
  • Typo Spam Traps (TST) – Similar to recycled Spam Traps, a typo spam trap is designed to give the impression of valid email addresses. However, they contain a subtly altered domain name that can easily fool the eye – e.g. instead of or instead of presence in the database can be completely accidental – resulting from a misspelt address on the registration form. Like recycled Spam Traps, typo Spam Traps are not as damaging as a pristine Spam Trap can be, but further mailings to such an address may signal that the sender does not care about the hygiene of its contact database and may prompt the provider to take further decisive steps. To rule out their appearance in the contact base, make sure that the sign-up form uses the double-opt-in method.
  • Inactive Spam Traps (IST) – This type of Spam Trap is not used as frequently but can still pose a threat to senders whose contact databases are not properly verified and cleaned. As their name suggests, they are invalid email addresses that have been unused for a long time – in most cases over one year – but have never been closed or deactivated by the ISP. Like RST traps, ISTs are often recycled from abandoned accounts and may have previously been active before being converted into Spam Traps (e.g., after moving to another provider). Therefore, it’s worth paying attention to them when cleaning up your database, although they will be far less common than other types of Spam Traps mentioned above. To avoid issues with these types of addresses in the future: make sure you regularly verify your mailing list using modern tools like Email Verify App, which ensure its cleanliness on an ongoing basis.”

Honeypot – a trap for spammers

When talking about Spam Traps, it is impossible not to mention a particular type of trap – the Honeypot. In cyber security, this term refers to a strategy that relies on the use of appropriately crafted methods (in this case, email addresses) to detect unauthorized processing and reveal the perpetrator.

Such Spam Traps are particularly troublesome for spammers because ISPs or anti-spam organizations do not wait until an address is in the subscriber’s database and someone accidentally sends an email to it.

These addresses are deliberately promoted and made public directly on websites or embedded in their code. Web scraping bots are able to find such addresses and collect them into their database.

Once emails start reaching the mailbox, the active spammer can be located, blocked, and reported to the relevant organization fighting spam.

This Spam Trap can therefore be compared to a pot of honey exposed to the sun – all you have to do is wait patiently, and the insects will be tempted to fly to it themselves.


How do we identify Spam traps?

We usually only become aware that Spam Traps may be present on our mailing list when the delivery rate starts to drop, and we have checked out other potential causes of this phenomenon.

Identifying specific Spam Trap email addresses is not easy – such information is not publicly available, as it would counter the purpose of their existence – spammers would easily exclude them. However, there are several ways to find potential Spam Traps – the key is to track engagement.

A recipient who doesn’t open your emails for several months, doesn’t complete orders, doesn’t use the password reminder, and doesn’t get in touch with you themselves (technical requests/complaints, etc.) could be a Spam Trap (or soon become one).

To be sure, you can segment your contact group and implement a reactivating campaign only for unengaged recipients. If your emails still do not get opened, remove such addresses from your mailing list. Even if they are not Spam Traps, the lack of any response can mean one thing – the recipients are not interested in receiving any correspondence from you.

There are also a number of paid tools available on the Internet that allow you to check for Spam Traps in your mailing list – some of the more popular ones are, for example, ZeroBounce or Email List Verify. You can upload your contact database to these platforms, and they will analyze it for you.

ZeroBounce – email address verification tool

Why it’s crucial always to check the list for spam traps?

“Spam Traps are an issue that every email marketer needs to be aware of. They can be detrimental to your sending reputation and completely damage the performance of your campaign,”
says Brian Minick, COO of email validation platform ZeroBounce.

“It’s important you are always checking to see if spam traps live on your list. While in theory a good sender would not have them, we’ve seen examples of even the best senders having them added to their newsletter sign-ups maliciously. You never know if they are lurking on your list as, in many cases, they appear to be just a normal looking email address. They’re also being created every day and new ones can appear. It’s critical you get these off and never send to them.
A good validation service such as ZeroBounce can ensure we help get them off your list.

How to avoid Spam Traps?

Fortunately, there are several ways to avoid Spam Traps. The most important thing is to verify the quality of your contact database on an ongoing basis. Some of the foolproof methods you can use to achieve this include the following:

  • don’t buy contact databases – to prevent Spam Traps, only use the addresses of recipients who have knowingly agreed to receive communications (in accordance with GDPR) and who actually want to receive communications from you,
  • use address validation through a double-opt-in mechanism in the sign-up form to eliminate typos leading to non-existent mailboxes,
  • block mailings to domains with the most common typos – e.g.,, etc. – by adding them to an internal blacklist in the EmailLabs interface,
  • only send to active and engaged contacts – take care to personalize and select relevant content,
  • regularly update your database – remove from it those contacts who do not open emails and are not engaged recipients and those who return Hardbounces.
  • use a tool to verify your mailing list for the presence of Spam Traps – it is worth considering investing in software that will scan and clean up your contact base before each send.

By following these simple rules, you will protect your emailing campaigns against the risk of being trapped by a Spam Trap.

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Spam Traps: Summary

What consequences you face when sending messages to spam trap addresses depends on the type of trap you get ‘caught in.’ If you make a single mailing to invalid addresses with a typo, there should be no reputational impact as long as it involves, for example, registering and sending a double opt-in message (to confirm enrolment), which will shut down further attempts to communicate with the same recipient.

However, multiple mailings to spam trap email addresses (especially a pristine spam trap) can have significant negative consequences – such as a weakening sender reputation, being blacklisted by RBLs, and a decrease in deliverability rates.

The fight against spam is constant. Every day, our inboxes are flooded with emails we do not want.

So let’s remember that Spam Traps are not intended to make it difficult for legitimate senders to carry out their mailings – those who take proper care of the hygiene of their mailing list and send out campaigns only to contacts interested in receiving emails from them, have nothing to fear.

Spam Trap email addresses are allies in the fight against spammers who block visibility in the mailbox for your messages – looking at them this way, you may find them a useful tool.

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