What 3rd party service do you use to collect sign ups?

Hi, I'll be sharing a demo video of my new VR game on Reddit very soon. As part of this post, I'll be including a link to a sign-up form where you can stay updated on the game's progress (also to gauge interest).

I wanted to reach out to the community and ask for your suggestions on email collection services. Currently, I'm familiar with Mailchimp, but I'd love to hear if there are any other services you recommend for collecting emails.