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Open Source Transactional Email Software (2026)
Last updated: March 2026
4 software options
Sponsored
Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews
Marketing Email, Transactional Email, Transactional SMS
Mailjet’s free plan gives you access to major features like 1,000 contacts, delivery and analytics dashboards, customer support, APIs and more. Send up to 6000 emails per month. Mailjet’s premium plans offer advanced features like Segmentation, A/B Testing, Email Automation and more. Mailjet works well with structure of all sizes and has a variety of plans for every needs, from Forever Free (6000 emails/month) to Custom Plans.
Read more about Mailjet
Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews
Integrate channels, become omnichannel
There are plans according the volume emails you will sent in a month.
Read more about emBlue
Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews
Cloud-based SMTP for email delivery
Kingmailer offers a free 14 day plan for testing purpose, and then scales up to a 1-month or 1-year plan. 1-Month Plan: $11.95 /month 1-Year Plan: $79 /year
Read more about KingMailer
Based on GetApp‘s extensive, proprietary database of in-depth, verified user reviews
A newsletter and email marketing plug-in.
Free plan allows to send unlimited number of emails, but doesn't give access to advanced statistics.
Read more about AcyMailing