Chatmail services optimized for Delta Chat apps

This repository helps to setup a ready-to-use chatmail server comprised of a minimal setup of the battle-tested postfix smtp and dovecot imap services.

The setup is designed and optimized for providing chatmail accounts for use by Delta Chat apps.

Chatmail accounts are automatically created by a first login, after which the initially specified password is required for using them.

Deploying your own chatmail server

We subsequently use CHATMAIL_DOMAIN as a placeholder for your fully qualified DNS domain name (FQDN), for example chat.example.org.

1. Install the cmdeploy command in a virtualenv

    git clone https://github.com/deltachat/chatmail
    cd chatmail
    scripts/initenv.sh
   

2. Create chatmail configuration file chatmail.ini:

    scripts/cmdeploy init CHATMAIL_DOMAIN
   

3. Setup first DNS records for your CHATMAIL_DOMAIN, according to the hints provided by cmdeploy init. Verify that SSH root login works:

    ssh root@CHATMAIL_DOMAIN
   

4. Deploy to the remote chatmail server:

    scripts/cmdeploy run
   

5. To output a DNS zone file from which you can transfer DNS records to your DNS provider:

    scripts/cmdeploy dns
   

Other helpful commands:

To check the status of your remotely running chatmail service:

scripts/cmdeploy status

To test whether your chatmail service is working correctly:

scripts/cmdeploy test

To measure the performance of your chatmail service:

scripts/cmdeploy bench

Overview of this repository

This repository drives the development of "chatmail instances", comprised of minimal setups of

• postfix smtp server
• dovecot imap server

as well as custom services that are integrated with these two:

• chatmaild/src/chatmaild/doveauth.py implements create-on-login account creation semantics and is used by Dovecot during login authentication and by Postfix which in turn uses Dovecot SASL to authenticate users to send mails for them.

• chatmaild/src/chatmaild/filtermail.py prevents unencrypted e-mail from leaving the chatmail instance and is integrated into postfix's outbound mail pipelines.

There is also the cmdeploy/src/cmdeploy/cmdeploy.py command line tool which helps with setting up and managing the chatmail service. cmdeploy run uses pyinfra-based scripting in cmdeploy/src/cmdeploy/__init__.py to automatically install all chatmail components on a server.

Home page and getting started for users

cmdeploy run also creates default static Web pages and deploys them to an nginx web server under https://CHATMAIL_DOMAIN.

• a default index.html along with a QR code that users can click to create accounts on your chatmail provider,

• a default info.html that is linked from the home page,

• a default policy.html that is linked from the home page.

All .html files are generated by the according markdown .md file in the www/src directory.

Refining the web pages

scripts/cmdeploy webdev

This starts a local live development cycle for chatmail Web pages:

• uses the www/src/page-layout.html file for producing static HTML pages from www/src/*.md files

• continously builds the web presence reading files from www/src directory and generating html files and copying assets to the www/build directory.

• Starts a browser window automatically where you can "refresh" as needed.

Emergency Commands to disable automatic account creation

If you need to stop account creation, e.g. because some script is wildly creating accounts, login to the server with ssh and run:

    touch /etc/chatmail-nocreate

While this file is present, account creation will be blocked.

Ports

Postfix listens on ports 25 (smtp) and 587 (submission) and 465 (submissions). Dovecot listens on ports 143(imap) and 993 (imaps).

Delta Chat apps will, however, discover all ports and configurations automatically by reading the autoconfig.xml file from the chatmail service.