GitHub stars · StarDay

1docker-mailserver / docker-mailserverAuthor description: Production-ready fullstack but simple mail server (SMTP, IMAP, LDAP, Antispam, Antivirus, etc.) running inside a container.ShellMIT · Permissive19,728

2Foundry376 / Mailspring:love_letter: A beautiful, fast and fully open source mail client for Mac, Windows and Linux.TypeScriptGPL-3.0 · Share derivative source17,995

3stalwartlabs / stalwartAll-in-one Mail & Collaboration server. Secure, scalable and fluent in every protocol (IMAP, JMAP, SMTP, CalDAV, CardDAV, WebDAV).RustLicense not declared15,766

4mailcow / mailcow-dockerizedA Docker-based email and groupware suite combining mail delivery and retrieval, spam filtering, webmail, and domain and mailbox administration.PHPGPL-3.0 · Share derivative source13,756

5Mailu / MailuInsular email distribution - mail server as Docker imagesPythonLicense not declared7,607

6pimalaya / himalayaCLI to manage emailsRustApache-2.0 · Permissive7,599

7jstedfast / MailKitA cross-platform .NET library for IMAP, POP3, and SMTP.C#MIT · Permissive6,870

8foxcpp / maddy✉️ Composable all-in-one mail server.GoGPL-3.0 · Share derivative source6,123

9twisted / twistedEvent-driven networking engine written in Python.PythonLicense not declared6,002

10imapsync / imapsyncImapsync is an IMAP transfers tool. The purpose of imapsync is to migrate IMAP accounts or to backup IMAP accounts. IMAP is one of the three current standard protocols to access mailboxes, the two others are POP3 and HTTP with webmails, webmails are often tied to an IMAP server. Upstream website isShellLicense not declared4,201

11neomutt / neomutt✉️ Teaching an Old Dog New Tricks -- IRC: #neomutt on irc.libera.chatCGPL-2.0 · Share derivative source3,860

12rustmailer / bichonBichon – A lightweight, high-performance Rust email archiver with WebUIRustAGPL-3.0 · Share derivative source2,068

13lavabit / magmaThe magma server daemon, is an encrypted email system with support for SMTP, POP, IMAP, HTTP and MOLTEN,. Additional support for DMTP and DMAP is currently in active development.CAGPL-3.0 · Share derivative source1,829

14cypht-org / cyphtCypht: Lightweight Open Source webmail aggregator [PHP, JS]. Supports IMAP/SMTP, JMAP and EWS (Exchange Web Services)PHPLGPL-2.1 · Share derivative source1,787

15flectar / mailBuilt from the ground up for speed. Flectar Mail delivers native performance, instant startup, and as little as 80 MB of RAM.RustAGPL-3.0 · Share derivative source1,781

16forwardemail / forwardemail.netPrivacy-focused encrypted email for everyone. All-in-one alternative to Gmail + Mailchimp + Sendgrid.JavaScriptLicense not declared1,701

17dovecot / coreDovecot mail serverCLicense not declared1,280

18kurrier-org / kurrierKurrier is a modern, self-hosted workspace for email, calendar, contacts and storage.TypeScriptLicense not declared1,071

19agenticmail / agenticmailEmail, SMS & phone-call infrastructure for AI agents — send and receive real email and text messages, and place agent-driven outbound voice calls, all programmaticallyTypeScriptMIT · Permissive247

20dmarcguardhq / parse-dmarcDMARC aggregate report parser with a built-in dashboard. One Go binary, IMAP in, SQLite, Prometheus metrics, MCP server. Apache-2.0.GoApache-2.0 · Permissive228