Ask HN: Is there a web app to collect emails?

I made a landing page for my startup, and I've so many things to do, so I'd prefer to save up energy and not setup Mailgun, a separate db table for emails, form validation and all that. Maybe there is a service that provides an iframe for email submission so that I could slap it on my landing page, and get my future users' emails in Airtable or something?