Although it is not explicitly stated, you are able to configure your Landingi lead pages to directly connect with autoresponder lists on SendFox using webhooks. This will allow Landingi to send lead information straight to SendFox via API.
Start in SendFox: Generate a List ID & API Personal Access Token Obtain a List ID
Generate an API Personal Access Token
Move over to Landingi: Configure lead capture form with Webhook
Left-Hand Field: Authorization Right-Hand Field: Bearer <API personal Access Token>