# Stalwart > Stalwart is an open-source mail and collaboration server written in Rust. A single binary implements JMAP, IMAP4, POP3, SMTP, CalDAV, CardDAV, and WebDAV, covering email, calendaring, contacts, and file storage. It is designed to run from a single-node personal deployment up to a clustered multi-node installation. This file indexes the official Stalwart documentation at https://stalw.art/docs. The documentation is the source of truth for configuration keys, protocol support, deployment topologies, and administration. The server source code lives in a separate repository at https://github.com/stalwartlabs. The documentation is versioned; links below point at the current release line. Older releases are available under `/docs//…` (for example `/docs/0.15/…`). ## Installation - [Getting started](https://stalw.art/docs/install/get-started): orientation for a new deployment. - [System requirements](https://stalw.art/docs/install/requirements): sizing, memory and CPU behavior under load. - [Install on Linux](https://stalw.art/docs/install/platform/linux): native install on Linux distributions. - [Install on Docker](https://stalw.art/docs/install/platform/docker): container deployment. - [Install on Windows](https://stalw.art/docs/install/platform/windows): native Windows install. - [Choose a storage backend](https://stalw.art/docs/install/store): how to pick a data store. - [Choose a directory](https://stalw.art/docs/install/directory): internal vs. external authentication directories. - [DNS setup](https://stalw.art/docs/install/dns): records required for SPF, DKIM, DMARC, MTA-STS, autoconfig and more. - [Securing the server](https://stalw.art/docs/install/security): hardening and access control. - [Performance tuning](https://stalw.art/docs/install/performance): caching and concurrency for high-traffic deployments. - [Upgrading](https://stalw.art/docs/install/upgrade): version-to-version upgrade notes. ## Email and collaboration - [Email store overview](https://stalw.art/docs/email/overview): JMAP/IMAP/POP3 mail storage model. - [Collaboration overview](https://stalw.art/docs/collaboration/overview): calendars, contacts, file storage, sharing. - [Calendaring (CalDAV)](https://stalw.art/docs/collaboration/calendar): calendar scheduling and CalDAV support. - [Contacts (CardDAV)](https://stalw.art/docs/collaboration/contact): address book and CardDAV support. - [File storage (WebDAV)](https://stalw.art/docs/collaboration/file-storage): file storage and WebDAV. - [Sharing](https://stalw.art/docs/collaboration/sharing): access control across calendars, address books and files. - [Scheduling](https://stalw.art/docs/collaboration/scheduling): iTIP/iMIP calendar scheduling. - [Notifications](https://stalw.art/docs/collaboration/notifications): push and email notifications. ## MTA (SMTP) - [MTA overview](https://stalw.art/docs/mta/overview): inbound and outbound SMTP pipeline. - [Inbound overview](https://stalw.art/docs/mta/inbound/overview): inbound session handling (connect, EHLO, MAIL, RCPT, DATA, AUTH). - [Outbound overview](https://stalw.art/docs/mta/outbound/overview): queue, routing, retry, quotas and rate limits. - [Filtering overview](https://stalw.art/docs/mta/filter/overview): Sieve, milter, MTA-hooks, and spam filtering. - [Sender authentication](https://stalw.art/docs/mta/authentication/spf): SPF, DKIM, DMARC and ARC verification. - [Reports](https://stalw.art/docs/mta/reports/overview): DMARC, TLS, and DSN reporting. - [Transport security](https://stalw.art/docs/mta/transport-security/overview): DANE, MTA-STS, and TLS reporting. - [Queue management](https://stalw.art/docs/mta/management): operating the outbound queue. ## Spam filter - [Spam filter overview](https://stalw.art/docs/spamfilter/overview): architecture of the built-in filter. - [Classifier overview](https://stalw.art/docs/spamfilter/classifier/overview): the linear spam classifier. - [LLM classification](https://stalw.art/docs/spamfilter/llm): using large language models for classification. - [DMARC check](https://stalw.art/docs/spamfilter/dmarc), [DNSBL](https://stalw.art/docs/spamfilter/dnsbl), [Greylisting](https://stalw.art/docs/spamfilter/greylist), [Phishing](https://stalw.art/docs/spamfilter/phishing): individual checks. - [Rules](https://stalw.art/docs/spamfilter/rules): custom rule definitions. - [Trusted senders](https://stalw.art/docs/spamfilter/trusted) and [Spam traps](https://stalw.art/docs/spamfilter/spamtrap). ## Sieve - [Sieve overview](https://stalw.art/docs/sieve/overview): server-side mail filtering language. - [ManageSieve](https://stalw.art/docs/sieve/managesieve): uploading and managing scripts. - [Interpreter overview](https://stalw.art/docs/sieve/interpreter/overview): evaluation semantics and extensions. - [Reference](https://stalw.art/docs/sieve/reference): supported commands and tests. - [Expressions](https://stalw.art/docs/sieve/expressions) and [Variables](https://stalw.art/docs/sieve/variables). - [LLM tests](https://stalw.art/docs/sieve/llm): invoking LLMs from Sieve. - [Examples](https://stalw.art/docs/sieve/examples). ## HTTP, JMAP and WebDAV - [HTTP overview](https://stalw.art/docs/http/overview): the HTTP service and endpoints. - [JMAP overview](https://stalw.art/docs/http/jmap/overview): JMAP Core and Mail endpoints, push, WebSockets. - [WebDAV overview](https://stalw.art/docs/http/webdav/overview): CalDAV, CardDAV, and WebDAV endpoints. - [Access control](https://stalw.art/docs/http/access-control): HTTP access control lists. - [Rate limiting](https://stalw.art/docs/http/ratelimit): request rate limits. - [HTTP security](https://stalw.art/docs/http/security): HTTP-layer hardening. - [Form submission](https://stalw.art/docs/http/form-submission): contact-form / webhook email submission. ## Authentication and authorization - [Auth overview](https://stalw.art/docs/auth/overview): identity model. - [Authentication overview](https://stalw.art/docs/auth/authentication/overview): passwords, app passwords, API keys, 2FA. - [OAuth overview](https://stalw.art/docs/auth/oauth/overview): OAuth 2.0 flows, tokens, client registration. - [OpenID Connect](https://stalw.art/docs/auth/openid): OIDC integration. - [Authorization overview](https://stalw.art/docs/auth/authorization/overview): roles, permissions, quotas, tenants. - [Directory backends](https://stalw.art/docs/auth/backend/overview): SQL, LDAP, OIDC and internal directory. - [Principals](https://stalw.art/docs/auth/principals/overview): accounts, groups, tenants. ## Storage - [Storage overview](https://stalw.art/docs/storage/overview): data, blob, FTS, lookup, and in-memory stores. - [Data store](https://stalw.art/docs/storage/data): metadata and indexes. - [Blob store](https://stalw.art/docs/storage/blob): raw message and file blobs. - [Full-text search](https://stalw.art/docs/storage/fts): FTS backends. - [In-memory store](https://stalw.art/docs/storage/in-memory): counters, tokens, and caches. - [Backends overview](https://stalw.art/docs/storage/backends/overview): RocksDB, FoundationDB, SQL, S3, and others. ## Server - [General settings](https://stalw.art/docs/server/general): top-level server configuration. - [Listeners](https://stalw.art/docs/server/listener): network listeners for each protocol. - [TLS overview](https://stalw.art/docs/server/tls/overview): certificates, ACME, and TLS configuration. - [DNS overview](https://stalw.art/docs/server/dns/overview): DNS resolver and provider integration. - [AI models](https://stalw.art/docs/server/ai-models): configuring LLM providers used by the server. - [Cache](https://stalw.art/docs/server/cache): in-process caches. - [Autoconfig](https://stalw.art/docs/server/autoconfig): autoconfig/autodiscover for mail clients. - [Auto-ban](https://stalw.art/docs/server/auto-ban): automatic IP banning. - [Reverse proxy](https://stalw.art/docs/server/reverse-proxy/overview): running behind nginx, HAProxy, Caddy, or Traefik. - [ASN](https://stalw.art/docs/server/asn): ASN-based controls. - [Enterprise features](https://stalw.art/docs/server/enterprise): features in the commercial edition. ## Configuration - [Configuration overview](https://stalw.art/docs/configuration/overview): how configuration works in Stalwart. - [Bootstrap mode](https://stalw.art/docs/configuration/bootstrap-mode): first-run bootstrap. - [Recovery mode](https://stalw.art/docs/configuration/recovery-mode): recovering from a broken configuration. - [Declarative deployments](https://stalw.art/docs/configuration/declarative-deployments): configuration-as-code deployments. - [Variables](https://stalw.art/docs/configuration/variables): template variables. - [Environment variables](https://stalw.art/docs/configuration/environment-variables): supported environment variables. - [Expressions](https://stalw.art/docs/configuration/expressions/overview): expression language used throughout the configuration. ## Domains and encryption - [Domains overview](https://stalw.art/docs/domains/overview): managing hosted domains. - [DNS records](https://stalw.art/docs/domains/dns-records): per-domain DNS records. - [TLS certificates](https://stalw.art/docs/domains/tls-certificates): ACME and manual certificates. - [DKIM rotation](https://stalw.art/docs/domains/dkim-rotation): rotating DKIM keys. - [Encryption overview](https://stalw.art/docs/encryption/overview): at-rest encryption for mail. - [PGP](https://stalw.art/docs/encryption/pgp) and [S/MIME](https://stalw.art/docs/encryption/smime): per-user encryption. - [Managing encryption](https://stalw.art/docs/encryption/manage). ## Cluster - [Cluster overview](https://stalw.art/docs/cluster/overview): multi-node deployments. - [Cluster configuration overview](https://stalw.art/docs/cluster/configuration/overview): node IDs, roles, and load balancing. - [Coordination overview](https://stalw.art/docs/cluster/coordination/overview): Kafka, NATS, Redis and peer-to-peer coordination. - [Orchestration overview](https://stalw.art/docs/cluster/orchestration/overview): Kubernetes, Docker Swarm, Apache Mesos. - [Deployment overview](https://stalw.art/docs/cluster/deployment/overview): sizing, storage, topology. ## Management and telemetry - [Management overview](https://stalw.art/docs/management/overview): administering a running server. - [CLI overview](https://stalw.art/docs/management/cli/overview): the `stalwart` CLI (get, query, create, update, delete, apply, snapshot). - [Web UI overview](https://stalw.art/docs/management/webui/overview): the admin web interface. - [Actions](https://stalw.art/docs/management/actions) and [Tasks](https://stalw.art/docs/management/tasks): operational actions and background tasks. - [Database maintenance](https://stalw.art/docs/management/maintenance/database) and [Migration](https://stalw.art/docs/management/maintenance/migration). - [Troubleshooting](https://stalw.art/docs/management/troubleshoot): diagnostic procedures. - [Telemetry overview](https://stalw.art/docs/telemetry/overview): metrics, traces, events. - [Metrics overview](https://stalw.art/docs/telemetry/metrics/overview), [Tracing overview](https://stalw.art/docs/telemetry/tracing/overview). - [Events](https://stalw.art/docs/telemetry/events), [Webhooks](https://stalw.art/docs/telemetry/webhooks), [Alerts](https://stalw.art/docs/telemetry/alerts), [Live view](https://stalw.art/docs/telemetry/live), [History](https://stalw.art/docs/telemetry/history). ## Reference - [Reference index](https://stalw.art/docs/ref): top-level reference index. - [Configuration objects](https://stalw.art/docs/ref): JMAP-object schemas for every configurable entity (accounts, domains, DKIM signatures, queues, certificates, and more). - [Permissions](https://stalw.art/docs/ref/permissions): all permission names. - [Events](https://stalw.art/docs/ref/events): all emitted events. - [Metrics](https://stalw.art/docs/ref/metrics): all exported metrics. ## Optional - [FAQ](https://stalw.art/docs/faq): frequently asked questions. - [Development API](https://stalw.art/docs/development/api): JSON management API. - [Compiling from source](https://stalw.art/docs/development/compile): building Stalwart from source. - [Database internals](https://stalw.art/docs/development/database): on-disk data layout. - [Supported RFCs](https://stalw.art/docs/development/rfcs): RFC compliance matrix. - [URN reference](https://stalw.art/docs/development/urn): internal URN scheme. - [Client applications](https://stalw.art/docs/applications/overview): recommended client applications. - [Blog](https://stalw.art/blog): release announcements and articles. - [0.15 documentation](https://stalw.art/docs/0.15/install/get-started): previous release line. - [GitHub](https://github.com/stalwartlabs): source code and issue tracker.