The Maileon integration lets you add subscribers to your Maileon contact list when they fill out an OptiMonk popup form — with the opt-in permission you choose, and with the extra data you want to store on the contact.

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 Maileon account.

1. Get your Maileon API key

Log in to your Maileon account and go to SETTINGS → API KEYS.

  • If you already have an API key, copy it.

  • If you do not, click Generate new API key. Choose any name you like, set the status to Active, and grant permission to create and update contacts. Without those permissions OptiMonk cannot add the subscriber.

OptiMonk's own hint for this field says: Please find the API key within Maileon account, under Settings then API keys options. (ex.: 9b6e40f4-db7b-4059-8d4a-2db082d709df)

2. Set up double opt-in in Maileon (optional)

If you want new subscribers to confirm their address, set the process up on the Maileon side first: Settings → Dispatches: Double Opt-In. You will then pick the matching permission level in OptiMonk in step 3.

3. Create a contact field for the source (optional)

If you want to segment your Maileon list by where the contact came from, create a field to store it: go to LISTS & CONTACTS → CONTACT FIELDS, click the green plus sign in the upper right corner of the list, choose a name, set the Field type to Text, and click create new contact field.

You will fill this field from OptiMonk in the field mapping step, as a static field.

4. Connect Maileon to your campaign

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

  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 Maileon. Use the Search providers… box if the list is long. If you have connected Maileon 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 — this is where opt-in is decided:

    • Opt-in permission — the permission level the new contact is created with: None, Single opt-in, Confirmed opt-in, Double opt-in, Double opt-in plus, Other. It starts on None, so set it deliberately.

    • Send double opt-in email — tick it to make Maileon send the confirmation email.

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

That's it. Whenever a visitor signs up through your popup, they are added to your Maileon contact 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

Maileon has no list to choose from, so the wizard's middle step is Settings instead of a list, and the mapping step comes right after it.

The mapping table has two columns: Popup field on the left (every input your popup collects) and Maileon field on the right. OptiMonk pre-fills it with its own suggestions.

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

  • Because Maileon is configured without a list, the right-hand column is a free-text box: Type the exact Maileon field or property name (e.g. first_name). Leave empty to skip a field. Type the contact field name exactly as Maileon spells it.

  • The source goes here too. Click Add static field, type the value on the left — any text, for example OptiMonk, or OptiMonk Winter Campaign if you want to tell campaigns apart — and name the contact field you created in step 3 on the right. That value is then sent with every signup.

Change or remove the integration

The Integrations tab lists every integration on the campaign, with the opt-in settings you picked shown underneath it.

  • Change list reopens the wizard at the Settings step, so you can change the opt-in permission or the mapping.

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