Open source. Open possibilities.

Novu is an open-source communication infrastructure that unifies notifications and agent messaging across Inbox, Email, SMS, Push, Chat, Slack, Teams and Telegram through one API and conversation model.

Soenneker.Loops.Contacts is a .NET utility library for managing Loops contacts by email. It provides create, update, find, and delete operations, configuration through a Loops API key, and scoped or singleton dependency injection registration.

React Email is a React + TypeScript component library for building responsive, dark-mode-aware emails, with an editor and integrations for major email providers.

Tomba is a CLI tool for finding and verifying email addresses, enriching contact data, and discovering phone numbers from domains, LinkedIn URLs, or article authors. It supports bulk CSV processing, AI chat, and reusable workflow skills.

Tuta Mail is a secure email service featuring built-in end-to-end encryption for communications across multiple devices.

Open-source Rust tool to verify email address existence without sending emails. Provides CLI, HTTP backend via Docker, and programmatic library with syntax, DNS, SMTP, and deliverability checks.