Stalwart IMAP Server
</h1>
Secure and Modern IMAP4rev2 server 🛡️
**Stalwart IMAP** is an open-source Internet Message Access Protocol server designed to be secure, fast, robust and scalable.
Key features:
- IMAP4 and ManageSieve server:
- IMAP4rev2 ([RFC 9051](https://datatracker.ietf.org/doc/html/rfc9051)) full compliance.
- IMAP4rev1 ([RFC 3501](https://datatracker.ietf.org/doc/html/rfc3501)) backwards compatible.
- ManageSieve ([RFC 5804](https://datatracker.ietf.org/doc/html/rfc5804)) server with support for [all extensions](https://www.iana.org/assignments/sieve-extensions/sieve-extensions.xhtml).
- Multiple IMAP extensions supported:
- Access Control Lists (ACL) ([RFC 4314](https://datatracker.ietf.org/doc/html/rfc4314))
- Conditional Store and Quick Resynchronization ([RFC 7162](https://datatracker.ietf.org/doc/html/rfc7162))
- SORT and THREAD ([RFC 5256](https://datatracker.ietf.org/doc/html/rfc5256))
- Message Preview Generation ([RFC 8970](https://datatracker.ietf.org/doc/html/rfc8970))
- And [many other extensions](https://stalw.art/docs/development/rfcs#imap4-and-extensions)...
- JMAP support:
- JMAP Core ([RFC 8620](https://datatracker.ietf.org/doc/html/rfc8620))
- JMAP Mail ([RFC 8621](https://datatracker.ietf.org/doc/html/rfc8621))
- JMAP over WebSocket ([RFC 8887](https://datatracker.ietf.org/doc/html/rfc8887))
- JMAP for Sieve Scripts ([DRAFT-SIEVE-13](https://www.ietf.org/archive/id/draft-ietf-jmap-sieve-13.html))
- Flexible and scalable:
- Pluggable storage backends with **RocksDB**, **FoundationDB**, **PostgreSQL**, **mySQL**, **SQLite**, **S3-Compatible**, **Redis** and **ElasticSearch** support.
- **Internal**, **LDAP** and **SQL** database authentication.
- Full-text search available in 17 languages.
- Disk quotas.
- 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.
- Integration with **OpenTelemetry** to enable monitoring, tracing, and performance analysis.
- Secure and robust:
- Encryption at rest with **S/MIME** or **OpenPGP**.
- Built-in Spam and Phishing filter.
- OAuth 2.0 [authorization code](https://www.rfc-editor.org/rfc/rfc8628) and [device authorization](https://www.rfc-editor.org/rfc/rfc8628) flows.
- Access Control Lists (ACLs).
- Rate limiting.
- Memory safe (thanks to Rust).
## Get Started
Install Stalwart IMAP 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).
> **Note**
> If you need a more comprehensive solution that includes an SMTP server, you should consider installing the [Stalwart Mail Server](https://github.com/stalwartlabs/mail-server) instead.
## Support
If you are having problems running Stalwart IMAP, you found a bug or just have a question,
do not hesitate to reach us on [Github Discussions](https://github.com/stalwartlabs/imap-server/discussions),
[Reddit](https://www.reddit.com/r/stalwartlabs) or [Discord](https://discord.gg/jVAuShSdNZ).
Additionally you may become a sponsor to obtain priority support from Stalwart Labs Ltd.
## 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
[email protected] for more details.
## Copyright
Copyright (C) 2023, Stalwart Labs Ltd.