Open source Email & Communication tools
15 free, open source options sorted by GitHub stars.
NtfySimple, fast, and secure push notifications for allBillion MailOpen-source mail server with unlimited sending & AI toolsInbox ZeroAI email assistant that automates, organizes, and decluttersTutaSecure email, calendar and contacts with end-to-end encryptionPlunkThe open-source, affordable email platformuseSendPay per email sent, not for contact storageFreescoutOpen-source helpdesk for seamless customer supportKeilaOpen-source email marketing for the privacy-consciousSendportalSelf-hosted email marketing with unlimited everythingUnInboxTransform team email into efficient collaborative workflowsDoubleZeroSelf-hosted email infrastructure for developersSessyOwn your SES email analytics, from send to inboxHyvor RelayOpen-source email API with enterprise deliverabilityTwake MailSecure open source email with advanced encryption & AIAgentMailEmail inbox API built for AI agents and workflows