Secure & Modern All-in-One Mail Server (IMAP, JMAP, POP3, SMTP) 🛡️


continuous integration   License: AGPL v3   Documentation

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## Features **Stalwart Mail Server** is an open-source mail server solution with JMAP, IMAP4, POP3, and SMTP support and a wide range of modern features. It is written in Rust and designed to be secure, fast, robust and scalable. Key features: - **JMAP** server: - [JMAP Core](https://datatracker.ietf.org/doc/html/rfc8620) and [JMAP Mail](https://datatracker.ietf.org/doc/html/rfc8621) full compliance. - [JMAP for Sieve Scripts](https://www.ietf.org/archive/id/draft-ietf-jmap-sieve-22.html) extension for managing Sieve scripts. - [JMAP for WebSocket](https://datatracker.ietf.org/doc/html/rfc8887), [JMAP Blob Management](https://www.rfc-editor.org/rfc/rfc9404.html) and [JMAP for Quotas](https://www.rfc-editor.org/rfc/rfc9425.html) extensions. - **IMAP4**, **POP3** and **ManageSieve** server: - [IMAP4rev2](https://datatracker.ietf.org/doc/html/rfc9051) and [IMAP4rev1](https://datatracker.ietf.org/doc/html/rfc3501) server with support for [numerous extensions](https://stalw.art/docs/development/rfcs#imap4-and-extensions). - [POP3](https://datatracker.ietf.org/doc/html/rfc1939) server with [extensions](https://datatracker.ietf.org/doc/html/rfc2449), [STLS](https://datatracker.ietf.org/doc/html/rfc2595) and [SASL](https://datatracker.ietf.org/doc/html/rfc5034) support. - [ManageSieve](https://datatracker.ietf.org/doc/html/rfc5804) server for managing Sieve scripts. - **SMTP** server: - Built-in [DMARC](https://datatracker.ietf.org/doc/html/rfc7489), [DKIM](https://datatracker.ietf.org/doc/html/rfc6376), [SPF](https://datatracker.ietf.org/doc/html/rfc7208) and [ARC](https://datatracker.ietf.org/doc/html/rfc8617) support for message authentication. - Strong transport security through [DANE](https://datatracker.ietf.org/doc/html/rfc6698), [MTA-STS](https://datatracker.ietf.org/doc/html/rfc8461) and [SMTP TLS](https://datatracker.ietf.org/doc/html/rfc8460) reporting. - Inbound throttling and filtering with granular configuration rules, sieve scripting and milter integration. - Distributed virtual queues with delayed delivery, priority delivery, quotas, routing rules and throttling support. - Envelope rewriting and message modification. - **Spam Phishing** filter: - Comprehensive set of filtering **rules** on par with popular solutions. - Statistical **spam classifier** with automatic training capabilities. - DNS Blocklists (**DNSBLs**) checking of IP addresses, domains, and hashes. - Collaborative digest-based spam filtering with **Pyzor**. - **Phishing** protection against homographic URL attacks, sender spoofing and other techniques. - Trusted **reply** tracking to recognize and prioritize genuine e-mail replies. - Sender **reputation** monitoring by IP address, ASN, domain and email address. - **Greylisting** to temporarily defer unknown senders. - **Spam traps** to set up decoy email addresses that catch and analyze spam. - **Flexible and scalable**: - Pluggable storage backends with **RocksDB**, **FoundationDB**, **PostgreSQL**, **mySQL**, **SQLite**, **S3-Compatible**, **Redis** and **ElasticSearch** support. - **Clustering** support with node autodiscovery and partition-tolerant failure detection. - Built-in, **LDAP** or **SQL** authentication backend support. - Full-text search available in 17 languages. - Sieve scripting language with support for all [registered extensions](https://www.iana.org/assignments/sieve-extensions/sieve-extensions.xhtml). - Email aliases, mailing lists, subaddressing and catch-all addresses support. - Automatic account configuration and discovery with [autoconfig](https://www.ietf.org/id/draft-bucksch-autoconfig-02.html) and [autodiscover](https://learn.microsoft.com/en-us/exchange/architecture/client-access/autodiscover?view=exchserver-2019). - Integration with **OpenTelemetry** to enable monitoring, tracing, and performance analysis. - Disk quotas. - **Web-based administration**: - Account, domain, group and mailing list management. - SMTP queue management for messages and outbound DMARC and TLS reports. - Report visualization interface for received DMARC, TLS-RPT and Failure (ARF) reports. - Configuration of every aspect of the mail server. - Log viewer with search and filtering capabilities. - Self-service portal for password reset and encryption-at-rest key management. - **Secure and robust**: - Encryption at rest with **S/MIME** or **OpenPGP**. - Automatic TLS certificate provisioning with [ACME](https://datatracker.ietf.org/doc/html/rfc8555) using `TLS-ALPN-01`, `DNS-01` or `HTTP-01` challenges. - OAuth 2.0 [authorization code](https://www.rfc-editor.org/rfc/rfc8628) and [device authorization](https://www.rfc-editor.org/rfc/rfc8628) flows. - Automated blocking of hosts that cause multiple authentication errors (aka **fail2ban**). - Access Control Lists (ACLs). - Rate limiting. - Security audited (read the [report](https://stalw.art/blog/security-audit)). - Memory safe (thanks to Rust). ## Screenshots ## Get Started Install Stalwart Mail Server on your server by following the instructions for your platform: - [Linux / MacOS](https://stalw.art/docs/install/linux) - [Windows](https://stalw.art/docs/install/windows) - [Docker](https://stalw.art/docs/install/docker) All documentation is available at [stalw.art/docs/get-started](https://stalw.art/docs/get-started). ## Support If you are having problems running Stalwart Mail Server, you found a bug or just have a question, do not hesitate to reach us on [Github Discussions](https://github.com/stalwartlabs/mail-server/discussions), [Reddit](https://www.reddit.com/r/stalwartlabs), [Discord](https://discord.gg/aVQr3jF8jd) or [Matrix](https://matrix.to/#/#stalwart:matrix.org). Additionally you may become a sponsor to obtain priority support from Stalwart Labs Ltd. ## Roadmap - [x] Performance enhancements - [x] Distributed SMTP queues - [x] Web-based admin panel - [ ] JMAP Calendar, Contacts and Tasks support - [ ] CalDAV and CardDAV support See the [open issues](https://github.com/stalwartlabs/mail-server/issues) for a full list of proposed features (and known issues). ## Funding Part of the development of this project was funded through the [NGI0 Entrust Fund](https://nlnet.nl/entrust), a fund established by [NLnet](https://nlnet.nl/) with financial support from the European Commission's [Next Generation Internet](https://ngi.eu/) programme, under the aegis of DG Communications Networks, Content and Technology under grant agreement No 101069594. If you find the project useful you can help by [becoming a sponsor](https://liberapay.com/stalwartlabs). Thank you! ## License Licensed under the terms of the [GNU Affero General Public License](https://www.gnu.org/licenses/agpl-3.0.en.html) as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. See [LICENSE](LICENSE) for more details. You can be released from the requirements of the AGPLv3 license by purchasing a commercial license. Please contact licensing@stalw.art for more details. ## Copyright Copyright (C) 2024, Stalwart Labs Ltd.