Both are the most popular self-hosted mail servers, and both deploy from our Marketplace in minutes. The difference is the size of the job: Mailcow — when you need mail, period: lightweight and easy to run. Zimbra — when you need a Google Workspace replacement: mail plus calendars, shared contacts and documents for a larger team. The detailed comparison is below.
Mailcow is a modern mail stack packaged in Docker: Postfix (SMTP), Dovecot (IMAP), Rspamd (antispam), SOGo (webmail and calendar) plus a clean admin panel. Its strengths are a fast start, DKIM out of the box, one-command docker compose updates and moderate requirements: for 5–100 mailboxes a 2 vCPU / 8 GB instance at ≈$22/mo is enough. It is the default choice for a small or mid-size business that wants reliable mail on its own domain without per-user fees.
Zimbra is more than mail — it is a collaboration platform: shared calendars, contacts, tasks, documents and a full web client. Effectively a self-hosted Google Workspace alternative for teams from 20 to 500+ users. The price is resources and complexity: the recommended start is 4 vCPU / 16 GB with 100+ GB of disk (≈$45/mo with a volume), and there are more components to maintain. An open-source edition exists; some enterprise features live in the paid Network Edition.
| Criterion | Mailcow | Zimbra |
|---|---|---|
| What it is | a modern mail stack in Docker | a full collaboration platform |
| Components | Postfix, Dovecot, Rspamd, SOGo webmail | mail, calendars, contacts, shared documents |
| Sweet spot | 5–100 mailboxes | 20–500+ users |
| Server requirements | moderate: 2 vCPU / 8 GB ≈$22/mo | higher: 4 vCPU / 16 GB + 100+ GB disk ≈$45/mo |
| Administration | easier: clean panel, docker compose updates | harder: more components and dependencies |
| DKIM / antispam | out of the box (Rspamd) | available, needs configuration |
| Clients | IMAP/SMTP + ActiveSync (SOGo) | IMAP/SMTP + native apps and sync |
| License | open source, free | open edition exists; advanced features in the paid Network Edition |
1. Do you need mail — or an “office”? Just mail with webmail — Mailcow. Company-wide shared calendars, contacts and documents — Zimbra.
2. Who will administer it? No dedicated admin — Mailcow is more forgiving; or plug in our Basic administration. With an IT team, Zimbra shows its full value.
3. What scale? Up to ~100 mailboxes Mailcow economics are better. From a hundred users with collaboration needs, Zimbra justifies its appetite.
Whichever server you pick, mail needs three things from the provider: an open port 25 (most clouds block it for new accounts — here it is open), a PTR/rDNS record (set in our panel in a minute) and correct SPF/DKIM/DMARC — about 15 minutes with our guide. Both images are in the Solution Marketplace: a server with mail preinstalled in minutes, hourly billing. Details and configurations — on the Corporate email page.
Can I migrate from Mailcow to Zimbra (or back)? Yes: mailboxes move with standard imapsync, DNS records point to the new server. Outgrowing Mailcow does not lock you in.
Which is cheaper to run? Mailcow: a smaller instance and fewer admin hours. For 30 mailboxes the difference is ≈$23/mo on the server alone.
Does SOGo replace Zimbra calendars? For basics — yes (calendar and contacts are there), but shared documents and granular permissions are exactly where Zimbra is stronger.
Is not Gmail/Workspace simpler? Simpler, but $7/user/mo: for 30 people that is over $200/mo versus ≈$22 for your own server. The bill and data control are the main reasons teams go self-hosted.
