Email newsletters and campaigns can be a very efficient way to communicate with your users. But managing the users that should receive each campaign can be a nightmare. Create a formula and let Liquid manage them for you.
When you use Liquid's Formulas, you'll select the audience, the action and the time.
Zapier integration with SendGrid to add users to mailing list subscribers
Activity based on event “Liked Fashion Item”
Select “All users” in the Audience screen.
Select Zapier as the action and past the Zapier url to integrate with Sendgrid.
Make the action Activity-based and select the option that is triggered by the “Liked Fashion Item” event.