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.

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.

With Mailchimp you can send newsletters and automated emails. You can build your email list with form or import your known contacts. Mailchimp offers pre-designed email templates and a drag and drop email builder.

Omnisend is an omnichannel marketing automation platform for ecommerce businesses. Omnisend allows you to add several channels to the same automation workflow for seamless communication via email, SMS, web push notifications, and more.

ActiveCampaign's platform gives businesses of all sizes access to hundreds of pre-built automations that combine email marketing, marketing automation, CRM, and machine learning for powerful segmentation and personalization across social, email, messaging, chat, and text.