Cumulus

SendGrid provides and manages an email server on your company's behalf, so your communications with customers are reliably sent and delivered as needed. It's perfect when you need to send transactional emails, password recovery emails or notifications to users from your website.

Shopify is a commerce platform that allows anyone to set up an online store and sell their products. It's the go-to eCommerce platform for young direct-to-consumer brands. It's ease of use and setup is what's most attractive to merchants, but also the incredibly vast Shopify app store.

Klaviyo is the best in class email marketing solution for eCommerce. It's powerful because it connects to your store, and you can create awesome customer segments based on past purchasing behaviors, customer preferences, and even future predictions of spending.