In general, the API integration is usually the best option for integrating Deadline Funnel with your email provider because it provides the most flexibility.
The API integration offers:
Streamlined setup for working with custom fields
The ability to trigger your Deadline Funnel at virtually any point in your email sequence or automation, not only when someone first opts in
Deadline Funnel currently has API integrations with:
Keap (Previously Infusionsoft)
If you are using an email provider we don't have an API integration with, then our optin form integration is a great option instead!
If you have any questions, please let us know at help@deadlinefunnel.com.