CrossBox can work alongside control panels but is also fully capable of running all on its own as a complete standalone solution.

What's Under The Hood

The standalone version comes prebuilt with everything you need to run your own modern communication suite.

MTA/Mail Server

Exim — a powerful MTA
Dovecot — an awesome mail server


Protocols to enable standard email access for any email app or webmail.


Advanced spam detection with Rspamd.


ClamAV for real-time email and file scanning.

Email Signing

DKIM, SPF, and DMARC support built-in.

Admin Area

An intuitive interface for administrators.

Server Settings

Tweak server settings according to your needs.

User Management

Manage users, domains and email accounts with ease.

Automatic Update

Keeps your CrossBox installation up to date automatically.


Used for video/audio relaying during calls and conferences. Can be configured to use an external one.


All services are preoptimized for concurrency and performance.


No need to waste time, everything is preconfigured to work out of the box.

External Relay

Ability to use a third-party email provider for relaying emails.

External Anti-spam

Ability to use a third-party anti-spam provider for spam filtering.


Comes with MySQL but can also use another local or external MySQL server.


Compatible with App Connector, Cluster and White-label

100% self-hosted

Everything runs and is hosted on your own server(s).

CrossBox Document Converter

Service that handles document conversions. Used by the File Previewer.

CrossBox Trusted-link

Service that proxies emails' assets through the server's SSL connection.

Let's Encrypt Built-in

Out of the box SSL support for all protocol thanks to the built-in Let's Encrypt plugin.

Modern Communication Suite On Your Own Server

Features usually available exclusively on big platforms like Gmail and Outlook are now a reality — on your own server.

Screen Sharing

There is no need to leave your Inbox and download a third-party app only to share a screen or collaborate with someone. Powerful s...

Email Follow-Ups

Need to do a follow-up on a conversation you had, but you may forget about it in a week? Create an email reminder to remind you —...

Email Composer

Why limit yourself to an inferior email editor? CrossBox has over 25 formatting options that allow you to style your email in deta...

Send Large Email Attachments

How many times you wanted to send an email with a couple of attachments only to find out that you can't — the email size limit is...

Super-Fast File Sharing

It's only natural that people participating in the channel want to share files with each other. CrossBox makes this an effortless...

Undo Button

How many times you deleted some emails and then realized that you would like to have them again? No problem — click the undo butto...

Call/talk to Anyone

Anyone can instantly join you in a channel or a call, just by clicking on a link in the invitation email. There are no forms to fi...

Email Snoozing

Emails are piling up, but you don't want to deal with them right now? With CrossBox, you can snooze any conversation. Just choose...

Attachment Previewer

Don't you hate downloading .docx and .xlxs files just to see what's inside? With CrossBox, you can preview any document, spreadshe...

Email Scheduling

You've just finished writing an email. But it's late. You wouldn't want to disturb anybody in the middle of the night! With CrossB...