Trashmail Plugin

This is a Postfix plugin to receive trashmail mails by SMTP via Postfix and save them into a MongoDB instance.

Prerequisites

To take advantage of this plugin you need following components:

• A running Postfix installation, which is able to receive smtp mails
• Python 3.6 or later, with following modules: ** eml ** pymongo
• A MongoDB installation
• Optional: trashmail-client, so users are able to retrieve mails

Installation

Create an user and group, e.g. trashmail, home directory can be /home/trashmail. Following examples presume home directory /home/trashmail.

• Clone this project to /home/trashmail.
• Create a directory /home/trashmail/.trashmail
• Create a config file /home/trashmail/.trashmail/lmtp-server.ini
• Create a log config file /home/trashmail/.trashmail/logging.ini

Contents of config files are explained in following sections.

Postfix Configuration

You need to do some configuration for Postfix to set up this tool. In main.cf you need following options:

/etc/postfix/relay_domains

Set up transport trashmail for each domain which you want to use with that plugin.

example.com    trashmail
example.net    trashmail

/etc/postfix/main.cf

At least Postfix needs to be configured to use relay_domains, usage of a map may be the best choice. Of course you may prefer other map type like ldap.

relay_domains = btree:/etc/postfix/relay_domains
transport_maps = btree:/etc/postfix/relay_domains

Feel free to use other Postfix mechanisms, there are no limitations regarding other Postfix options.

/etc/postfix/master.cf

To use transport trashmail it is necessary to define it in this file.

trashmail   unix  -       n       n       -       -       pipe
  flags=FR user=trashmail argv=/home/trashmail/postfix-plugin/main.py
  ${client_address} ${client_hostname} ${sender} ${recipient}

You may select an other location for trashmail plugin, e.g. for use with Posfix chroot option.

Trashmail Config File

Config file is expected on location ~/.trashmail/lmtp-server.ini, format:

[DEFAULT]
mongo_url = mongodb://127.0.0.1:27017/
mongo_db = trashmail-lmtp
max_age = 60

mongo_url and mongo_db must match your MongoDB installation. Option max_age is used for clean up process to remove messages older than max_age from MongoDB. Postfix plugin does not care about this parameter.

Logging Config Files

For syntax and options regarding logging see [2], following a small example:

[loggers]
keys=root,mail.log,internal_checks,lmtp,config,storage

[handlers]
keys=consoleHandler

[formatters]
keys=simpleFormatter

[logger_root]
level=DEBUG
handlers=consoleHandler

MongoDB

It is recommended to use a Docker container for MongoDB. Due to typical trashmail use cases, persistent storage is not necessary.

docker run -d -p 27017:27017 -v ~/data:/data/db mongo

Links

[1] [https://docs.python.org/3/library/logging.html] Python3 Logging module

[2] [https://docs.python.org/3/library/logging.config.html] Python3 Logging configuration module