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Introduction to OpenEMAIL

OpenEMAIL Overview

OpeneEMAIL: It is Free, Open Source, and Dockerized Mail Server.

It is your mail server. It is Open Source. It is production ready. It is secure. It is fast. Zero initial configurations. It can be deployed in few minutes. It can be updated in few minutes. It is license free and limitless. Use it for your business. Earn money by selling support. Use it as a comprehensive production use case lab in your Docker training classes at least.

At Cybergate our effort is to consolidate the best available open source email, collaboration, and email security solutions to provide you highly agile, secure, and enterprise ready world class, Open Source email and collaboration platform that can easily replace any other equivalent commercial alternative.

We have borrowed some excellent ideas from existing dockerized email projects, specially from Mailcow and MailU But we are significantly different from them specially in the areas of comprehensive deployment guide, providing migration tools to migrate your existing mail setup like Zimbra, Office365, Gmail, providing additional tools for administration and integration.

Our near future plans will be to integrate OpenEMAIL with FreeIPA to provide Kerberos Single Sign On for webmail users.

Integrated Web UI

Our administration Web UI which started as fork of Mailcow project and extending it as we are adding new features. We are deeply indebted to their excellent effort in making such a good consolidation of all complex backend email tools into a single pane of Web UI by making it very easy for administrators to manage the system without using complex command line tools and configuration file editing.

Dockerized and Cloud Ready

All the backend applications of OpenEMAIL are running in Docker Containers by making OpenEMAIL a software that is ready to deploy in your private or public cloud infrastructure and utilize the benefit of agility and elasticity of modern day cloud computing.

OpenEMAIL Architecture Overview

Following figure depicts how OpenEMAIL docker application containers are interconnected internally and how they are being accessed externally.


OpeneEMAIL Demo

You can find a demo at, use the following credentials to login:

User Role URL User Password
Super Administrator admin openemail
Domain Administrator domainadmin openemail
Maibox User openemail
Webmail Access openemail

OpenEMAIL Feature Overview

The integrated OpenEMAIL UI allows administrative work on your mail server instance as well as separated domain administrator and mailbox user access:

  • DKIM and ARC support
  • Black- and whitelists per domain and per user
  • Spam score management per-user (reject spam, mark spam, greylist)
  • Allow mailbox users to create temporary spam aliases
  • Prepend mail tags to subject or move mail to sub folder (per-user)
  • Allow mailbox users to toggle incoming and outgoing TLS enforcement
  • Allow users to reset SOGo ActiveSync device caches
  • imapsync to migrate or pull remote mailboxes regularly
  • TFA: Yubikey OTP and U2F USB (Google Chrome and derivatives only), TOTP
  • Add domains, mailboxes, aliases, domain aliases and SOGo resources
  • Add whitelisted hosts to forward mail to mailcow
  • Fail2ban-like integration
  • Quarantine system
  • Antivirus scanning incl. macro scanning in office documents
  • Integrated basic monitoring
  • A lot more...

OpenEMAIL Containers

OpenEMAIL comes with multiple containers linked in one bridged network. Each container represents a single application.

Container Service
Dovecot IMAP/POP3 services
ClamAV (optional) Antivirus service for Rspamd to scan mails for email viruses
Solr (optional) Email indexing and Full Text Search service for Dovecot
Oletools via Olefy Helper socket to use oletools with rspamd for scanning Microsoft OLE documents
Memcached A general-purpose distributed memory caching system
Redis An in-memory data structure store, used as a database, cache and message broker
MySQL MariaDB database
Postfix Postfix MTA Service
ACME-Client Let's Encrypt client for automatic SSL certificate creation
Nginx Nginx web server
Rspamd Spamfiltering
SOGo Email groupware, ActiveSync and webmail service
Netfilter Fail2ban-like netfilter integration by @mkuron
phpmyadmin PHP web based administration for MariaDB
db-backup Runs a service that periodically backups MariaDB databases
backup Runs Duplicati backup service for OpenEMAIL
apps Runs Heimdall Application Dashboard for OpenEMAIL
rainloop Runs optional Rainloop webmail application for OpenEMAIL
rouncube Runs optional Roundcube webmail application for OpenEMAIL
dockerapi API for interacting with the Docker daemon
Watchdog basic container monitoring service

OpenEMAIL Docker Volumes

Docker volumes are used to keep dynamic data of the containers. We need to take care of them as they contain persistent data of containers. We need to backup them regularly. You will learn how to do it in Backup and Restore section of this document.

Volume Name Contents
vmail-vol-1 Dovecot mailbox data
vmail-attachments-vol-1 Dovecot email attachments data with deduplication
mysql-vol-1 MariaDB database Container data
mysql-socket-vol-1 MariaDB Unix Socket for local access
sogo-web-vol-1 Sogo groupware container data
solr-vol-1 Apache Solr container data
redis-vol-1 Redis container data
mysql-vol-1 MariaDB Container data
rspamd-vol-1 Rspamd container Data
postfix-vol-1 Postfix container data
crypt-vol-1 Dovecot mailbox encryption keys

Get Support

If you think that you need our support then we are ready to help you. We have several ways of giving you support.

Commercial Support

For commercial support contact or get a support subscription at Cybergate.

Community Support

Create an issue in our GitHub repository below.

GitHub @ openemail

Hosted OpenEMAIL

A fully featured, cloud based, managed OpenEMAIL is also available. Please contact Amila kothalawala on +(94)77 316 545 for more details.

Service Level Agreement

You can download our Support Level Agreement Here and review it before contacting our sales hot-line +(94) 766 783 783 for further details

Migrate to OpenEMAIL

You can easily migrate from Zimbra, Gmail, Microsoft Exchange or Office 365 hosted email or any other email service without compromising any of those major email and collaboration features like Addressbook, Calendar, Task and Contact sharing, public folders, resource sharing, Microsoft Outlook and Mobile Sync with native ActiveSync protocol.

The Freedom of Choice

You are well aware that email is by far the most widely used business application of the Internet. From a single owner business to a large enterprise primarily rely on email as their first line of business communication. The intention of this comprehensive free guide is to help you getting OpeneEMAIL deployed free if you have in house systems engineering skills. OpenEMAIL is 100% free in terms of software licensing that blocks you from scaling your business.

OpenEMAIL Security

Following is a brief overview of email security tools that are implemented in OpenEMAIL.

DNS Security

OpenEMAIL takes security as then priority. Currently OpenEMAIL supports almost all DNS based email security features like SPF,DKIM, DMARC etc,


It is backed by Rspamd, a fast, free and open-source spam filtering system where you do not need to make any other investment on spam filtering.


Integrated Sanesecurity ClamAV signatures will improve ClamAV detection rate on Macro malware, Javascript malware, Phishing, Spam and other emailed Ransomware upto 90%. This makes your emails free from viruses and malware without an additional financial investment.


python-oletools is a package of python tools to analyze Microsoft OLE2 files (also called Structured Storage, Compound File Binary Format or Compound Document File Format), such as Microsoft Office documents or Outlook messages, mainly for malware analysis, forensics and debugging. It is based on my olefile parser.

Fail2ban-like Netfilter

Fail2ban-like netfilter iptables integration by @mkuron


The Postfix postscreen(8) daemon provides additional protection against mail server overload. One postscreen(8) process handles multiple inbound SMTP connections, and decides which clients may talk to a Postfix SMTP server process. By keeping spambots away, postscreen(8) leaves more SMTP server processes available for legitimate clients, and delays the onset of server overload conditions.

Two-Factor Authentication

Openemail supports multiple domains in a single installation with domain based administration and Two-Factor Authentication making the delegation of administration is breezy, easy, and secure.

Openemail supports two-factor authentication for Web UI making it more secure when using web based administration

Per User Spam Filtering

You can fine grain Openemail's spam filtering backend per email box basis by making it is the most flexible in spam managing.

Backup and Restore

Openemail has provided you all required tools for backing up and restoring by helping administrators to have a goodnight sleep and enjoy their holidays. You can sync your backup to your own FTP server or any other public cloud storage like Amazon S3, Google Bucket or any other.