Top IMAP GitHub Repositories & Tools (2026)

Built from the ground up for speed. Flectar Mail delivers native performance, instant startup, and as little as 20 MB of RAM.

Self-hosted mail server for your own domain: SMTP/IMAP/POP3, CardDAV/CalDAV, React webmail and admin console, one-command Docker Compose.

Cypht: Lightweight Open Source webmail aggregator [PHP, JS]. Supports IMAP/SMTP, JMAP and EWS (Exchange Web Services)

A cross-platform .NET library for IMAP, POP3, and SMTP.

Emails at the heart of your business logic!

💌 Mail app for Nextcloud

Homebrew tap for PHP extensions :beers:

Official master for the Greenmail project

An email parser written in PHP

Terminal-based email client for Linux and macOS

DavMail POP/IMAP/SMTP/CalDAV/CardDAV/LDAP Exchange and Office 365 Gateway - Synced with main subversion repository at

Built-in Mail & Calendars app clone for Windows.