Spring Cleaning Part I: Growing an Organic Email List

Mallory Mongeon | 2015-04-23T17:15:35+00:00 | email on acid logo

Spring has sprung. Though you may already be planning to sweep out your garage, now is a good time to give your email list a thorough cleaning, too. But first things first. Before we dig into the nitty-gritty details of cleaning and maintaining your email list, let’s talk about how to build a healthy list from the start.

Grow your list organically

The number one tactic for organic list growth is gating content with an opt-in form. Whether it’s a marketing guide, webinar or your monthly newsletter, if you provide fantastic information, people will be willing to exchange their email addresses for it. Other simple ways to grow your list include online contests or sweepstakes, promoting webinars on social channels and paid advertisements. The sky’s the limit.

When growing your list organically, you can do so through a single opt-in or double opt-in process. In case you need a refresher, here’s the difference:

  • Single opt-in: Someone fills out a registration or subscription form and is automatically added to your email list.
  • Double opt-in: After someone signs up for your mailing list, you send a confirmation link in an email that they must click before they are added to your list.

Many marketers automatically choose the single opt-in method because they want to gain as many leads as possible. However, you should be sure to think through this decision. If your goal is to grow a list of subscribers that will be engaged with the emails you send, opening a confirmation email and clicking on a link should only serve to prove their interest.

MailChimp tested this theory when they took a random sample of 30,000 users in their database who’d sent at least 10 campaigns to see if double opt-ins improved their email marketing stats. Check out the results below.


The double opt-in method produced a 72.2% increase in unique opens. Double opt-in lists also had a 114% increase in clicks compared to the click through rate of single opt-in lists.

Never purchase an email list

Whether you choose to leverage a single or double opt-in method is up to you, but never (never!) buy a list! The surest way to become infected with spam traps is by purchasing email lists.

Purchased lists are potentially full of bad and out-of-date data. Unfortunately, you cannot tell how old email addresses are and, as we established previously, about 25% of them expire each year. Sending to these bad addresses can get you flagged as spam or even blacklisted. Not to mention that sending to thousands of people that did not opt-in will inevitably hurt your brand, sender score and email metrics.

Beware of old email address spam traps

Dead and dormant addresses can turn into spam traps. Email addresses that were once owned by customers of the ISP/email provider and are no longer in use are turned off to return a hard bounce or SMTP error message to senders after a defined, but undisclosed period of inactivity. This process is known as “gravestoning.” After an email address has been gravestoned for 30 to 90 days, depending on the ISP, some addresses will be reactivated to become spam traps. Any email delivered to these accounts is recorded as a spam trap hit.

If you regularly scrub your list of hard bounces (which we will talk about in Spring Cleaning Part 2), you don’t have to worry about falling into this trap. However, if you keep hard bounces on your list or buy a list, your reputation can take a hit by sending to gravestoned accounts.

Typo traps are alive and well

In December 2012, Spamhaus introduced a new kind of spam trap called typo traps. Typo traps are email addresses that contain common typos, usually in the domain, like “jennifer@gnail.com” instead of “@gmail.com.” Spamhaus believes that these mistakes are usually introduced when email addresses are being collected at point of sale (which is probably an accurate assumption).

This kind of spam trap is more about encouraging best practices like cleaning your list or running your addresses through a verification process to ensure they are legit. Also, if you use the double opt-in method, a typo trap will never make it onto your list. Typo traps did not cause deliverability issues initially, but that has changed. Recently, GAP was blacklisted because of the many typo traps they triggered in their mailing campaigns.

Don’t cut corners when building your email list

Building your list through a strictly opt-in basis can be tedious, but remember that quality trumps quantity. By purchasing a list, you’re running the risk of gaining unqualified leads, or even worse… fake and malicious email addresses. Ensure you’re protecting your sender reputation and in turn, your brand, through organic list building practices.

Now that you’ve built a healthy list from the ground up, we’ll discuss nurturing your list through email hygiene practices in part 2 of our spring cleaning edition. Stay tuned!

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