Stalwart Mail Server review
A capable self-hosted mail stack with collaboration services, clustering and a free Community edition.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Stalwart Mail Server is a self-hosted mail and collaboration platform from Stalwart Labs for organizations running their own infrastructure. It combines JMAP, IMAP4rev1, IMAP4rev2, POP3 and SMTP services with calendars, contacts and file storage through CalDAV, CardDAV and WebDAV. Web-based administration, automated DNS, DKIM and TLS management, built-in spam and phishing filtering, clustering, high availability, fault tolerance and distributed SMTP queues make it suited to teams that want control over their mail environment rather than a hosted mailbox service.
Pricing is structured around a free Community edition and annual Enterprise licenses. Community costs $0 per server and is AGPL-3.0 licensed, with self-hosted deployment and standard mail and collaboration protocols. Enterprise starts at $2.40 per mailbox per year for 25–499 mailboxes, then costs $2.04 for 500–999, $1.74 for 1,000–4,999, $1.48 for 5,000–10,000, $1.25 for 10,000–49,999, and $1.09 for 50,000–99,999. Enterprise plans include unlimited domains, tenants, mailing lists and aliases, enterprise features, and licenses installable on unlimited servers. A 30-day free trial is also available.
Its ecosystem fit is practical for open-source infrastructure teams: supported clients and services include Apple Calendar, Apple Contacts, Mozilla Thunderbird, GNOME Evolution, KDE Kontact, and iOS and Android CalDAV/CardDAV clients. AI integrations include OpenAI, Anthropic and OpenAI-compatible self-hosted LLM endpoints. The main boundary is the user-facing mail experience: the current web interface is administration and account-management focused, while a dedicated built-in webmail client was planned but not an immediate priority. Choose Stalwart for self-hosted control, protocol coverage and collaboration services; choose another product if a built-in webmail client is central to the deployment.
Stalwart Mail Server pros and cons
- Where it wins
- Free AGPL-3.0 Community edition for self-hosted deployments
- JMAP, IMAP, POP3, SMTP and built-in filtering
- CalDAV, CardDAV, WebDAV, clustering and distributed queues
- Where it doesn't
- Self-hosted deployment requires your own infrastructure
- Web interface focuses on administration and account management
- Enterprise pricing varies by mailbox range and annual billing
Stalwart Mail Server fact sheet, pricing and score →
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