How to Avoid Fake Leads and Maintain List Quality

You’ve launched your lead gen campaign, and the form is doing its job — leads are coming in fast. But here’s the problem: a significant chunk of those email addresses might be completely fake.

Whether it's bots filling out the forms, users typing gibberish to bypass signup walls, or disposable email services slipping through your form, fake emails can silently kill your marketing performance.

In this guide, we’ll walk you through the practical steps you can take with Mailmodo to keep your list clean and high-quality.

4 key tactics to prevent fake emails in your lead forms

Here’s a curated list of practical tactics you can implement to identify and prevent fake leads from making it into your workflow.

1. Send confirmation emails and segment verified users

Send a confirmation email or a double opt-in email immediately after form submission, asking users to click a button or link to confirm their email.

How to implement in Mailmodo:

1. Open your Mailmodo dashboard and go to Journey → Create Journey → Start from Scratch.

2. Select Web Forms as your trigger, then click Configure Trigger and set up the trigger.

3. In the journey builder, drag the Send Campaign block and link it to your trigger.

4. Add an email template with a confirmation form to the campaign block.

5. Add ‘Add contact to a list’ block to add the verified users to a new list.

6. Launch the flow and you’ll have a verified list of emails in the new list.

2. Segmentation and suppression in Mailmodo

Even if a fake email gets into your system, it won’t behave like a real user. You can use Mailmodo’s dynamic segmentation to filter these out over time.

In Mailmodo, you can create a dynamic segment using the AI segmentation feature or define the rules of the segment yourself like “segment contacts who have not opened or clicked any email within a given timeframe (e.g., 14 or 30 days)”.

Additionally, if the emails are fake and not deliverable, the emails bounce and Mailmodo automatically suppresses their emails, so no emails are sent to them in the future.

3. Manually detect fake emails

Fake email addresses have patterns that you can easily spot, including:

• Random strings of letters and numbers, such as 'asdkjfh2345@example.com'

• Obvious placeholders like 'test@test.com' or 'abc@abc.com'

• Disposable domains, such as 'someone@mailinator.com' or '10minutemail.net'

• Broken formatting with no @ symbol or a domain that does not exist

In Mailmodo, you can:

1. Export your contact list or form submissions.

2. Filter or search for suspicious strings.

3. Tag them as suspicious_email or move them to a suppression list.

4. Create a new sheet with clean emails and upload them to a new list as a CSV.

Doing this manually might sound tedious, but it sets a clean baseline and helps your team recognize spammy patterns in the future.

4. Add basic form-level human verification

Adding a human verification method provides a strong first line of defense against spammy contacts. You can implement this protection directly on your form or landing page.

Here are a couple of ways to do it:

• Google reCAPTCHA: Prevents bot entries before submission.

• Simple logic questions: Add a required field like “What is 3 + 14?” that bots can’t easily bypass.

Final thoughts

Keeping your lead capture forms free of fake emails is crucial for maintaining a healthy, high-performing email list. By combining proactive verification, engagement-based cleaning, and pattern detection, you can ensure that your campaigns reach real, interested users.

Mailmodo makes this process easier with features like confirmation emails, dynamic segmentation, and suppression lists. Pair these tools with simple form-level protections, such as CAPTCHA or logic questions, and rules to block duplicate submissions.