Prevent Duplicate Newsletter Subscriptions with Contact Form 7

Introduction

Managing newsletter subscriptions effectively is crucial for maintaining a clean and engaged subscriber list. One common issue faced by website administrators is duplicate email entries. This can lead to inefficiencies and a poor user experience. In this blog post, we'll explore how to prevent duplicate email submissions in Contact Form 7 using a custom PHP function.

Why Prevent Duplicate Entries?

Duplicate entries can clutter your database, lead to multiple emails being sent to the same user, and generally create a messy subscriber list. By preventing duplicates, you ensure that each subscriber is unique, which can improve your email marketing efforts and provide a better user experience.

Implementing the Solution

To prevent duplicate email submissions, we can use a custom PHP function that hooks into Contact Form 7's validation process. This function checks if the submitted email already exists in the database and, if it does, returns an error message to the user.

Step 1: Add the Custom PHP Function

Add the following code to your theme's functions.php file or a custom plugin:

add_filter('wpcf7_validate_email*', 'cfdb7_prevent_duplicate_email', 20, 2);

function cfdb7_prevent_duplicate_email($result, $tag) {

    global $wpdb;

    if ('your-email' == $tag->name) { // Replace with your actual email field name

        $email = sanitize_email($_POST[$tag->name]);

        $exists = $wpdb->get_var($wpdb->prepare(

            "SELECT COUNT(*) FROM {$wpdb->prefix}db7_forms WHERE form_value LIKE %s",

            '%' . $wpdb->esc_like($email) . '%'

        ));

        if ($exists) {

            $result->invalidate($tag, "This email has already been submitted.");

        }

    }    

    return $result;

}

            

Step 2: Create the Contact Form 7 Form

Next, create a simple Contact Form 7 form for newsletter subscriptions. Here's an example:

<div class='news-latter'>

   [email* your-email autocomplete:email] 

   [submit "subscribe"]

</div>

            

Step 3: You can also add this css.

			.news-latter p {

    display: flex;

    justify-content: center;

    flex-wrap: nowrap;

    align-items: baseline;

}		

Conclusion

By implementing this custom PHP function, you can effectively prevent duplicate email submissions in your Contact Form 7 forms. This ensures a cleaner database and a better experience for your users. If you have any questions or need further assistance, feel free to leave a comment below!