Connect WordPress to Listmonk
If you run a WordPress site and your newsletter lives on Listmonk — self-hosted or on a managed host like Yellaro — a free plugin connects the two. Signups from any form on your site flow straight into a Listmonk list, with optional opt-in at WooCommerce checkout.
This post is the why and the context. For the exact, click-by-click setup as a Yellaro customer, follow the step-by-step guide: How to connect a WordPress signup form to your newsletter. The short version and the reasoning are below.
The plugin
The tool is Integration for listmonk, maintained by post-duif — free and open source, and it works with both self-hosted and managed Listmonk. Pair it with WPForms (the free version is fine) for a signup form, and optionally WooCommerce if you want customers to opt in at checkout.
Setup, in short
The mechanics are simple: you give the plugin four things — your Listmonk URL, an API username, an API token, and your list's numeric ID — then point a WPForms form at it. When someone submits the form, their email lands in your list.
If you're on Yellaro, you don't create any of that yourself. A scoped Integration token, its username, and your list IDs are already made for you and shown on your dashboard's Integrations page — you just copy them into the plugin. The WordPress signup guide walks through every field, including the WooCommerce checkout opt-in. (On a bare self-hosted Listmonk you'd wire up your own API credentials, which is outside the scope of this post.)
A gotcha worth knowing about
One quirk of the plugin catches people out. When you go back to edit any setting later, the API access token field appears blank, with a "leave blank to keep the current token" style hint underneath.
In practice, saving the settings page with that field empty can wipe your stored token, and the plugin then fails silently — your form still says "Thanks for signing up," but nothing reaches your list. The fix: re-paste your token every time you save the plugin settings. Keep it in a password manager so it's one copy-paste away. This is a plugin UI quirk, not a Listmonk or Yellaro problem.
A note on security
The token you paste into WordPress is worth understanding. On Yellaro it's tightly scoped: it can add subscribers and read your lists, and that's all. It can't send campaigns, change settings, or touch your account — so even if it were exposed, the blast radius is small. Someone with it could add subscribers to a list; nothing more.
That's a deliberate contrast with a generic Listmonk API user, which typically carries broad admin rights. If you're self-hosting, it's worth scoping your own API user the same way and rotating the token periodically.
Why this is worth doing
Most WordPress newsletter setups end up at Mailchimp or similar, where a growing list means a growing bill — and the marketing-suite features you're paying for are often ones a plain newsletter never touches.
Listmonk keeps it lean. You host the software yourself, or use a managed provider that does it for you. On a managed host like Yellaro, pricing is by subscriber tier but far cheaper — from €8/month — with unlimited sending on every plan, so emailing your list more often never changes the bill. Either way the WordPress side is the same few minutes of configuration; the only difference is where the email addresses end up, and what you pay once they're there.