Verteilzentrum

A minimalistic mailing list

Verteilzentrum is a minimalistic mailing list following the KISS philosophy.

Features:

Single config file
Multiple lists
Blacklisting
Whitelisting
Persistent Receivers
Configurable publishing rights
Sending through an external MTA

Installation

Install golang (>=1.15), gcc, make and build-essential if you don’t have them already
Clone the repository: git clone https://github.com/bn4t/verteilzentrum.git
Checkout the latest stable tag
Make sure go is in your $PATH and run make build to build the verteilzentrum binary
Run sudo make install to install verteilzentrum on your system. This will create the directories /etc/verteilzentrum (config directory) and /var/lib/verteilzentrum (data directory). Additionally the user verteilzentrum will be created.
If you have systemd installed you can run sudo make install-systemd to install the systemd service. Run service verteilzentrum start to start the verteilzentrum service. Verteilzentrum will automatically run as the verteilzentrum user.

You can make certificates and private key files accessible to the verteilzentrum user with the following command:
````shell script
setfacl -m urx


#### Increasing deliverability
To increase deliverability it is recommended to set up an [SPF](https://en.wikipedia.org/wiki/Sender_Policy_Framework) and [DMARC](https://en.wikipedia.org/wiki/DMARC) record for the MTA. 
# How to use
#### Subscribing to a list
Send an email (content doesn't matter) to `subscribe+$list_name`. E.g. `subscribe+news@lists.example.com`.
You will receive a confirmation email that subscribing was successful.
#### Unsubscribing from a list
Send an email (content doesn't matter) to `unsubscribe+$list_name`. E.g. `unsubscribe+news@lists.example.com`.
You will receive a confirmation email that unsubscribing was successful.
# Config
By default the config is located at `/etc/verteilzentrum/config.toml`.
## General options
#### logging
The logging level for verteilzentrum.
Can be one of the following:
- `DEBUG` => Everything is logged
- `INFO` => Everything is logged except debug messages
- `ERROR` => Only errors are logged
#### bind_to
The address including port on which the server should listen for non tls connections.
Listens by default on `0.0.0.0:25`.
#### bind_to_tls
The address including port on which the server should listen for tls connections.
Can be left empty if no tls certificates are configured.
Listens by default on `0.0.0.0:465`.
#### hostname
The hostname of the list server. If you specify a TLS certificate it has to be valid for this hostname.
#### read_timeout
SMTP read timeout in milliseconds.
#### write_timeout
SMTP write timeout in milliseconds.
#### max_message_bytes
Maximum incoming message size in bytes.
#### tls_cert_file
Path to the TLS certificate file.
#### tls_key_file
Path to the corresponding private key to the TLS certificate. 
To disable inbound TLS just comment out both TLS settings.
#### data_dir
The location where all persistent data is stored.
#### mta_address
The address of the mta used to send mailing list messages.
This mta is used to send messages for all configured mailing lists including subscription notifications.
#### mta_auth_method
The auth method used for authentication to the mta.
Can be either `PLAIN` or `ANONYMOUS`.
#### mta_username
The username used for authentication to the mta.
#### mta_password
The password used for authentication to the mta.
#### Example
````toml
[verteilzentrum]
logging = "INFO"
bind_to = "0.0.0.0:25"
bind_to_tls = "0.0.0.0:465"
hostname = "lists.example.com"
read_timeout = 100000
write_timeout = 100000
max_message_bytes = 1048576 # 1024 * 1024
tls_cert_file = "/some/path/cert.pem"
tls_key_file = "/some/path/key.pem"
data_dir = "/var/lib/verteilzentrum"
mta_address = "smtp.example.com"
mta_auth_method = "PLAIN"
mta_username = "lists@example.com"
mta_password = "secret"

Lists

Lists are represented as toml tables in an array.

Table elements

name

The name of the list which also serves as the list address.

persistent_receivers

Array of email addresses which always receive mailing list messages regardless of whether they are subscribed.

whitelist

Array of whitelisted email addresses which are allowed to interact with the list. Supports wildcards.

If empty the whitelist is disabled.

blacklist

Array of blacklisted email addresses.

Blacklisted addresses are not allowed to interact in any way with the list. Can be empty. Supports wildcards.

Important: The Blacklist has a higher priority than the whitelist.

can_publish

Array of email addresses which are allowed to publish messages to the list. Supports wildcards.

Example

[[list]]
name = "private-list@lists.example.com"
persistent_receivers = []
whitelist = ["hostmaster@example.com","john@example.com"]
blacklist = []
can_publish = ["hostmaster@example.com"]
[[list]]
name = "public-list@lists.example.com"
persistent_receivers = ["archive@example.com"]
whitelist = []
blacklist = ["spam@example.com"]
can_publish = ["moderator@example.com", "admin@example.com"]

For further examples take a look at the example config.

Command line flags

-config <config file> - The location of the config file to use. Defaults to config.toml in the working directory.

Deinstallation

Run sudo make uninstall to uninstall verteilzentrum.
This will remove the verteilzentrum binary and the directories /etc/verteilzentrum and /var/lib/verteilzentrum if they are empty.

To remove the systemd service run sudo make uninstall-systemd.

Contributing

Feel free to send patches to me@bn4t.me or to open pull requests on Github.

License

This project is licensed under the GPL version 3 and later. See the LICENSE file.