Integrating Mailigen with OptiMonk lets you send your leads straight to Mailigen and turn them into customers with its email marketing system. Everyone who fills out your popup form is added to the Mailigen list you pick — no exports, no copy-paste.

Before you start: you need a campaign whose popup is already built (the field mapping is read from the input fields of your popup) and a Mailigen account.

1. Get your Mailigen API key

Open a new tab and log in to your Mailigen account. Click the Settings icon (the gear symbol) in the upper-right corner, then choose API Keys. If you do not have a key yet, click Add a key to generate one, then copy it.

OptiMonk's own hint for this field says: You can view or generate API keys in your Mailigen account. Go to Settings -> API keys.

2. Connect Mailigen to your campaign

  1. Open Campaigns in the left menu and click the campaign you want to connect with Mailigen.

  2. Open the Integrations tab of the campaign.

  3. Click Add integration. If this is the campaign's first one, the same step is offered as Connect your email or SMS tool.

  4. Provider step: pick Mailigen. Use the Search providers… box if the list is long. If you have connected Mailigen before, the account is listed at the top under Your connected accounts — pick it there and jump to step 6.

  5. Account step: paste the key into API key, optionally give the connection a name (Name (optional)), and click Connect. OptiMonk checks the credentials right away: if they are wrong, the step says Connection failed — check the credentials.

  6. Settings step:

    • List — the Mailigen list your leads will be added to.

    • Double opt-in — tick it if a new subscriber should confirm their address before Mailigen starts sending to them.

    • Update existing contacts — tick it if someone who is already on the list should be updated with the new data instead of being skipped.

  7. Click Continue, then on the Field mapping step decide where each popup field goes in Mailigen (see below), and click Save integration.

That's it. Whenever a visitor signs up through your popup, they are added to your Mailigen list. Their data also stays in OptiMonk — you find it under Leads in the left menu.


Draft vs. live: if the campaign has not been published yet, the integration is shown with a Draft pill and the note Saved as draft — it goes live when you publish the campaign. On a published campaign it shows as Active and is applied right away.

Field mapping, and sending the source

There is no longer a separate First name, Last name, Source URL and Source selector. Instead, one table maps everything: Popup field on the left (every input your popup collects) and Mailigen field on the right. OptiMonk pre-fills it with its own suggestions, so first name and last name are usually matched for you — you only need to check it.

  • The email row is fixed — it always maps to the Mailigen email field.

  • Pick Don't sync for any popup field you don't want to send.

  • The source goes in as a static field. Click Add static field under Static fields, type the value on the left — for example OptiMonk, or OptiMonk Winter Campaign if you want to tell campaigns apart — and choose the Mailigen field on the right. That value is sent with every signup.

There is no default value any more: if you want a source on the contact, add the static field. Leaving it out simply means nothing is sent there.

Change or remove the integration

The Integrations tab lists every integration on the campaign with its list name.

  • Change list reopens the wizard at the Settings step, so you can change the list, the two switches or the mapping.

  • Remove takes the integration off this campaign: Remove from this campaign? The account connection stays and can be added again. Your Mailigen credentials are not deleted, so you can reuse them on another campaign.