Modoboa — Open Source Mail Hosting and Management Platform
General Information
Modoboa sits in the category of tools that try to make email hosting less painful without hiding what’s really happening under the hood. At its core it’s just Postfix and Dovecot, but with an admin layer, webmail, calendars, and some reputation tooling glued together. The point is not to reinvent mail — it’s to run it with sane defaults and give admins a web console that covers the daily chores.
It appeals to small providers, schools, and IT teams that don’t want Exchange-sized baggage but still need a full stack: domains, quotas, antispam, DKIM/DMARC, and a way for users to log in without fiddling with config files.
How It Works
Mail transport is handled by Postfix, storage by Dovecot. Amavis sits in front with SpamAssassin and ClamAV, filtering junk before it reaches the inbox. The Radicale service adds CalDAV/CardDAV so calendars and contacts sync with phones and desktops.
The webmail interface is bundled in, so users don’t have to be trained on third-party clients, though any IMAP client works just as well. Admins manage everything from a browser: create domains, set mailbox quotas, rotate DKIM keys, or check mail traffic graphs. TLS is baked in, with Let’s Encrypt support out of the box.
Functions
| Feature | In practice |
| Platforms | Best supported on Debian/Ubuntu Linux |
| Mail stack | Postfix (SMTP), Dovecot (IMAP/POP3) |
| Webmail | Built-in client with search, folders, and signatures |
| Groupware | Radicale for calendars and contacts (CalDAV/CardDAV) |
| Filtering | Amavis frontend with SpamAssassin + ClamAV |
| Security | TLS/SSL, Let’s Encrypt, SPF/DKIM/DMARC checks |
| Admin panel | Web console for domains, users, quotas, traffic stats |
| Extensibility | Feature set delivered as extensions |
| License | ISC license |
Installation Guide
1. Bring up a Debian/Ubuntu server.
2. Pull the installer:
git clone https://github.com/modoboa/modoboa-installer
cd modoboa-installer
3. Run the setup with your domain:
sudo ./run.py example.com
This sets up Postfix, Dovecot, Amavis, the web panel, and DKIM signing.
4. Add DNS records (MX, SPF, DKIM, DMARC).
5. Log in to the admin panel and create the first mailboxes.
For non-Debian systems, components need to be installed manually, piece by piece.
Everyday Use
– Small hosters use it to run a dozen customer domains on a VPS with quotas and antispam turned on.
– Schools and NGOs keep it on-prem to stay clear of SaaS providers while still offering webmail and calendars.
– Corporate IT often runs it internally for lab or departmental mail, where control and isolation matter more than fancy collaboration.
Day to day it means resetting a password, checking spam queues, or tweaking Sieve filters for a noisy user — routine admin work.
Limitations
– The official installer targets Debian/Ubuntu; other distributions mean extra manual work.
– Spam and virus filtering is heavy on RAM. Under 4 GB the system struggles if traffic is high.
– It doesn’t aim to be a full collaboration suite — no document editing or chat built in.
– Ecosystem is smaller than what you’d get with Zimbra or commercial groupware stacks.
Comparison
| Tool | Platforms | Strengths | Best Fit |
| Modoboa | Linux (Debian/Ubuntu) | Full mail stack with admin panel, modular extensions | SMEs, hosters, on-prem deployments |
| Roundcube | Multi-platform | Mature standalone webmail | Existing mail stacks needing only a client |
| SOGo | Linux | Groupware with ActiveSync, good Outlook support | Orgs focused on calendar/contact sync |
| Zimbra OSE | Multi-platform | Enterprise-grade groupware, broad ecosystem | Large schools, enterprises |
| hMailServer | Windows | Lightweight server, easy to manage | Windows-centric environments |
Notes from the Field
Admins usually mention that the installer saves hours of manual setup, but DNS work still decides whether mail lands in inboxes or spam folders. Let’s Encrypt automation is appreciated — one less thing to forget. A common practice is to allocate more memory than the minimum so spam and AV filters don’t choke. Overall, teams see Modoboa as a pragmatic middle ground: not as heavy as Exchange or Zimbra, but not as barebones as a standalone Postfix + Roundcube build.