Spam trap email addresses
A spam trap address is one where any email received at that address is usually considered spam. If you send email to such addresses, you risk being labelled a spammer. Which is why spam traps are of interest to email marketers.
Where do they come from?
There are many different types of spam traps, but the ones most relevant to email marketing are honeypot and dormant addresses.
Honeypots
Spammers compile lists of email addresses to send their spam to. Or they sell such lists to other spammers. They often get these addresses by roaming the Web looking for any email address listed on a website. If they find one, they copy the address and put it on their list.
This process is known as email address harvesting and is usually automated using special "address harvesting" software.
Some organizations involved in tackling spam put specific email addresses on a website for the sole purpose of attracting harvesting software.
These addresses are never used for any other purpose: they are merely listed on a web page in such a way that no human would ever discover them or seek to send email to them. Address harvesting software can dig them out of a website, though.
Any email sent to such "honeypot" addresses must, by definition, be spam. The address owner never added the email voluntarily to any email list: they just put it up on a website. So it must have been harvested by a spammer and added without permission to a mailing list.
Organizations monitor their honeypot addresses to help them identify both spam emails and their sources.Dormant addresses
Email accounts often fall into disuse. They are abandoned by their owners or shut down: as a result the account is unable to receive email.
Legitimate senders of email will stop sending messages to such addresses. They notice a dead address and remove it from their system. Spammers will just keep on sending regardless.
So some organizations (like webmail services) will take dead email accounts and, after a suitable period of time has elapsed, repurpose them as spam traps.
What happens if you mail a spam trap?
If you send an email to a spam trap then that hurts your reputation as a sender of email with the organization managing the incoming email.
The exact consequences are impossible to quantify, given the variety of spam traps and organizations involved. But one thing is sure: sending email to spam traps gets you another tick on the "is this a spammer?" checklist. So it can mean your email is given closer scrutiny or even blocked from delivery.
Spammers send email to spam traps. You don't want to be a spammer, so don't send email to spam traps.
How do you identity spam traps?
The above is easy advice if we could identify spam trap addresses. But we usually can't. They're not supposed to be identifiable, otherwise they wouldn't work as spam traps.
So prevention is better than cure.
Ordinarily, spam traps are not a problem if you're following email marketing best practices and only sending email to people who specifically requested those emails and continue to want those emails.
By definition, your emails would then never hit a spam trap address.
Honeypot addresses typically only land on your list if you're doing something inadvisable and spam-like, such as harvesting email addresses or buying lists of email addresses.
Occasionally, some malicious entity will actively submit spam trap addresses to your list. If you require new subscribers to confirm their subscription by clicking on an email link, then the spam trap address will of course never get confirmed and will not be added to your list.
This closed-loop opt-in approach (often called double opt-in) is thus the best way to ensure a "clean" email list. (See here for a more detailed discussion of confirmation emails and spam traps.)
Spam traps that are converted dormant addresses can, however, get on your list. Someone might sign up for your newsletter, then leave their job and close down the email address they gave you. In time that address might be converted to a spam trap.
However, any professional email marketing software or service will recognize an address that no longer accepts email and automatically delete it from your list long before it's converted into a spam trap.
So the basic advice is this: get permission before adding an address to your list, possibly using the closed-loop opt-in approach. And use professional software or services that keep your list clean of redundant addresses.
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