Head-to-head · Mail Server Software
Stalwart Mail Server vs Cyrus IMAP
Stalwart Mail Server leads on 0 checks, Cyrus IMAP on 0, and 6 are even. Who comes out ahead on the 6 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.
Our verdict
- Highest scoreStalwart Mail Server · 6.9/10
- Free planboth
- Free trialonly Stalwart Mail Server
- Most featuresStalwart Mail Server · 4 of 5
Stalwart Mail Server scores higher on our rubric for mail server software: 6.9 against 6.5 out of 10; our editors rank them #23 and #27.
Stalwart Mail Server is the better fit for modern, low-cost open-source mail hosting. Cyrus IMAP is the better fit for mature, scalable IMAP infrastructure.
- Stalwart Mail Server fits best
Modern, low-cost open-source mail hosting
- Cyrus IMAP fits best
Mature, scalable IMAP infrastructure
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Side by side
| Feature | Stalwart Mail Server 6.9/10 Visit ↗ | Cyrus IMAP 6.5/10 Visit ↗ |
|---|---|---|
| At a glance | ||
| Editor score | 6.9 | 6.5 |
| Ranking | #23 in Mail Server Software | #27 in Mail Server Software |
| Best for | Modern, low-cost open-source mail hosting | Mature, scalable IMAP infrastructure |
| Pricing model | Free plan + paid | Free |
| Starting price | $1.09/user/yr | Free plan |
| Free plan | ✓ | ✓ |
| Free trial | 30 days | — |
| Deployment | Self-hosted, Browser extension | Self-hosted |
| Platforms | Web, Linux | Linux |
| Support | Community, Docs | Community, Docs |
| Built for | Small business, Mid-market, Enterprise | Small business, Mid-market, Enterprise |
| Features Stalwart Mail Server 4/5 · Cyrus IMAP 3/5 | ||
| Webmail interface | — | — |
| IMAP/POP3 access | ✓ | ✓ |
| Mobile sync | ✓ (best) | Not checked yet |
| Antispam tools | ✓ | ✓ |
| High availability | ✓ | ✓ |
| Specs | ||
| License model | Open-source | Open-source |
| Mailbox limit | 25 mailboxes | Not checked yet |
| Our review | ||
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| Our verdict | 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… Read the review → |
Cyrus IMAP is open-source server software for organizations that need to manage email, contacts, and calendars on their own infrastructure. It supports mailbox access through IMAP, IMAPS, POP3, POP3S, and JMAP, while CalDAV and CardDAV… Read the review → |
Strengths and trade-offs
Stalwart Mail Server — 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
Cyrus IMAP — where it wins
- Supports IMAP, POP3, JMAP, CalDAV, and CardDAV access
- Includes quotas, ACLs, Sieve filtering, replication, and clustering
- Handles SPF, DKIM, DMARC, antivirus, and antispam tool support
Where it doesn't
- Requires Linux infrastructure managed by the operator
- Does not provide a webmail interface
- Cyrus Murder is not a true high-availability solution
- Stalwart Mail Server6.9/10 · Free plan · 30-day trial
A capable self-hosted mail stack with collaboration services, clustering and a free Community edition.
Visit StalwartFull verdict → - Cyrus IMAP6.5/10 · Free plan
A mature, scalable choice for organizations managing their own IMAP infrastructure.
Visit Project CyrusFull verdict →
All mail server software comparisons → · Full ranking →
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Last updated · How we research and update