I’ll add some more here… Keep in mind these companies all have a strong reputation in the email marketing industry and offer a range of features and tools for creating and sending newsletters, automating email campaigns, and analyzing email marketing performance. It’s worth noting that each ESP has its own unique features and pricing plans, so it’s a good idea to compare them to determine which one might be the best fit for your needs.
Mailchimp: An all-in-one marketing platform that allows users to create and send newsletters, automate email campaigns, and analyze marketing performance.
Campaign Monitor: A tool for creating, sending, and analyzing email marketing campaigns.
ConvertKit: An email marketing platform specifically designed for professional bloggers and content creators.
Drip: An email marketing platform that helps businesses drive customer loyalty and revenue growth through automation.
GetResponse: A comprehensive email marketing solution with tools for creating and sending newsletters, automating campaigns, and analyzing marketing performance.
AWeber: An email marketing platform with tools for building and sending newsletters, automating campaigns, and analyzing marketing performance.
ActiveCampaign: A customer experience automation platform with email marketing capabilities.
Constant Contact: An email marketing platform with tools for creating and sending newsletters, automating campaigns, and analyzing marketing performance.
HubSpot: A marketing, sales, and customer service platform that includes email marketing capabilities.
Infusionsoft: A sales and marketing automation platform with email marketing capabilities.
Mad Mimi: A simple email marketing platform with drag-and-drop newsletter creation and automation tools.
Marketo: A marketing automation platform with email marketing capabilities.
Omnisend: An email marketing platform with tools for creating and sending newsletters, automating campaigns, and analyzing marketing performance.
Sendinblue: An email marketing platform with tools for creating and sending newsletters, automating campaigns, and analyzing marketing performance.
VerticalResponse: An email marketing platform with tools for creating and sending newsletters, automating campaigns, and analyzing marketing performance.
I would add Emarsys (owned by SAP) to this list. Oracle also has a capability (Responsys) but has cut investment and jobs in the business unit which included Responsys
There is a vendor based here in Ireland - Sensorpro - they have a Shopify product (UI needs work) but really solidly built. Good RFM capabilities on flows. Epicor and Kentico white label their email.