MailerLite

Overview

MailerLite is an email marketing platform founded in 2010 and headquartered in Vilnius, Lithuania, with additional offices in San Francisco and London. It is popular with small businesses, freelancers, bloggers, and content creators for its clean interface, generous free tier, and GDPR-friendly European data residency. MailerLite provides email campaign management, automation workflows, A/B testing, subscriber segmentation, pop-up and embedded signup form builders, and a landing page creator. On host websites, MailerLite appears through its embeddable form widgets — inline subscription forms, pop-up overlays, and slide-in banners — that capture email addresses for list building.

What This Script Does

The MailerLite script loads from static.mailerlite.com and renders email signup form widgets on the host page. The script handles form display logic, animation, submission handling, and conditional display rules.

Cookies and identifiers set:

• MailerLitePopupCookie — Form suppression cookie set when a visitor dismisses or submits a MailerLite popup; prevents the same form from appearing again for a configured period; expiry typically 30–365 days depending on the form's configured suppression window.
• ml_subscriber_id — Subscriber identifier cookie set on the host domain when a visitor submits a form; links the browser to the MailerLite subscriber record; expiry 1 year.
• Session storage key ml_form_shown_<form_id> — Tracks which forms have been displayed in the current session to prevent duplicate impressions.

Script filenames and CDN: embed.min.js or universal.js loaded from static.mailerlite.com. Form configuration and group data fetched from api.mailerlite.com/api/v2/forms/<form_id>/. Submissions POSTed to api.mailerlite.com/webforms/landing/<form_id>/subscribe.

Per-submission data collected:

• Email address (required)
• Optional fields: name, phone, custom subscriber fields defined by the list owner
• Source URL and referrer at time of submission
• Form identifier and subscriber group assignment
• UTM parameters present in the URL at time of form display

Email tracking (in-email context): MailerLite campaigns include 1x1 open tracking pixels hosted at link.mailerlite.com and click-redirect links. These report email engagement metrics (open rate, click rate, device type) to the list owner's dashboard but operate in the email client context, not on the website.

Form display logic: The script evaluates display conditions in real time — scroll percentage, time on page, exit intent mouse position, page URL patterns — to determine when to surface a popup or slide-in. This requires continuous page interaction monitoring while the script is active.

Consent & Compliance

MailerLite is classified under the marketing category. The signup form widgets collect personal data (email addresses) for marketing communications and transmit them to a third-party marketing service. Under GDPR Article 6(1)(a) and the ePrivacy Directive, the persistent ml_subscriber_id cookie and any exit-intent or behavioural display logic require prior opt-in consent. The form submission itself constitutes the consent basis for email marketing, but the script's continuous page interaction monitoring and cookie-setting operate independently. MailerLite as a Lithuanian company processes data under EU jurisdiction, providing a favourable GDPR transfer basis. Under CCPA/CPRA, email collection for marketing must be disclosed with appropriate opt-out rights.

Should You Block This Without Consent?

Yes. MailerLite scripts set subscriber identification cookies and monitor page behaviour for form display triggers. Block MailerLite tracking and form scripts until marketing consent is granted.