Alternativ till Mailtrain för Software as a Service (SaaS) med gratis licens

• Software as a Service (SaaS)
  Alla plattformar Windows Mac Linux Chrome OS Android iPhone Apple Watch iPad Android Tablet Windows S Web Self-Hosted Software as a Service (SaaS) Shopify Magento Community Edition WooCommerce Amazon SES (Simple Email Service) Zapier Facebook Ads
• Gratis licens
  Eventuell licens Gratis licens Open Source-licens Kommersiell licens