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MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Lotame - Make your data actionable, learn about your most valuable customers, improve ROI by targeting the right audience and increase relevance across screens.
Brevo - Innovative online Email Marketing solution to manage your contacts, create & send your newsletters and track your results. More than 80 000 clients. Best prices and attractive features.
Google Audience Center - 3 votes and 6 comments so far on Reddit
Campaign Monitor - Email marketing software built for designers and their clients to run successful email campaigns.