How to Secure Your Sign-Up Forms and Keep Spam Out

By The Grey Retention Team |  22 Min Read | Updated on January 28th, 2024

A sign-up form is a direct, straightforward way to convert website visitors into email and SMS subscribers—and eventually, customers. A secure sign-up form not only keeps bots and bad actors out, but also sets your marketing campaigns up to be more valuable by ensuring that the people receiving your emails and text messages definitely want your content.

Think of it this way: A secure sign-up form makes life difficult enough that bad actors go away, while keeping it easy for visitors to convert into subscribers and customers.

Why Secure Sign-Up Forms Matter

Unfortunately, if you send or receive email, gather email addresses, or have anything to do with email at all, you know about spam. Spam is a consistently frustrating issue, particularly for business owners and email marketers. While you aim to gain more subscribers to help your business grow, you’ll also encounter fake or spam signups that complicate your marketing campaigns.

Part of the challenge is keeping your forms protected without making it too complicated for legitimate users. Here are some ways to prevent bots or other spam sign-ups and keep your forms working properly for genuine new contacts.

What is a Spambot?

A spambot is a malicious program designed to gather email addresses and information from online sources like forms, chat rooms, and websites. This information is usually gathered to build lists for sending unsolicited emails spam.

How to Secure Your Sign-Up Forms

Here are three easy ways to make your sign-up forms more secure:

1. Implement a Double Opt-In Process

Also known as confirmed opt-in, double opt-in is a simple process in which someone enters their email address or phone number into your form and clicks “Subscribe.” They then receive an email or a text containing a link to confirm their subscription. Their subscription is only confirmed after they click on the link.

Benefits of Double Opt-In:

  • Increased Legitimacy: Since double opt-in relies on access to the inbox—which is more secure than a web form—it significantly increases the likelihood of a legitimate subscription. Even if a bot abuses your sign-up form, they won’t be able to join your list without accessing the confirmation email or text.
  • Human Confirmation: Inbox providers usually classify a subscription confirmation email as a transactional message, making it less likely to be scanned by bots. Thus, any click on that email is more likely to be from a human.
  • Willing Consent: Everyone who joins your list has completed two separate actions to confirm they want to hear from your brand, indicating a higher likelihood of engagement with your content.

For SMS specifically, Klaviyo’s Smart Opt-In feature allows visitors to quickly join your list with a one-time passcode. This seamless process keeps visitors on your site so they can get back to shopping in seconds and satisfies double opt-in, which is highly recommended when collecting SMS consent.

2. Use CAPTCHA on Your Sign-Up Forms

You’ve likely experienced situations where a web form asks you to type the correct alphanumeric combination you see or select all the images that have motorcycles in them. These challenges are known as CAPTCHA, and they’re designed to make it difficult for bad actors to abuse your forms.

How CAPTCHA Works: The goal of CAPTCHA is to challenge the entity making the request to prove it’s human. Because the challenge combination that needs to be solved can be near-infinite, CAPTCHA is hard enough that bad actors are forced to move on. Services like reCAPTCHA can help you implement this protective step for free.

3. Add a List Verification Service to Your Tech Stack

Using a list verification service to screen addresses is probably the most expensive and resource-intensive method to secure your sign-up form, but it can be worth it.

How It Works: When a visitor enters an email address into your form, an API call checks that email address against the list verification service’s database. Some services also offer additional options, such as checking to ensure the email address has the correct format or preventing the use of certain addresses or domains.

Sign-Up Form Security: A Vital Piece of a Strong Marketing Program

These three methods are the most common and effective ways for brands to secure their sign-up forms. While they’re effective at keeping many bad actors away, it’s also important to continue refining your email marketing program by segmenting your lists and implementing sunset flows to ensure you’re only sending relevant content to engaged subscribers.

Power Smarter Digital Relationships

If you don’t prevent the majority of spam signups, you compromise the integrity of your entire email marketing program. A mix of legitimate and fake email addresses sets you up for failure when you send an email campaign. Not only will you potentially damage your sender reputation with a high invalid email count, but you’ll also make it harder for mail to reach the real people who want your messages. Recipient servers start to filter or reject mail from domains that send too many emails to bad addresses.

Spam isn’t going anywhere anytime soon, so take the time to implement one or more of these ideas. You’ll save time and effort in the long run. A combination of different methods will be the most powerful, but even a single reCAPTCHA checkbox can help you prevent spambots without complicating your sign-up process.

Ready to Secure Your Sign-Up Forms?

Implement these strategies to ensure that your sign-up forms remain effective and secure. By doing so, you’ll protect your email marketing efforts and ensure that your messages reach the right audience. For more tips and advanced strategies, contact us today and let’s take your email marketing to the next level.