Mailman

3.3.10 verified Fri May 01 auth: no python

Mailman is the GNU mailing list manager, a Python library for running and managing mailing lists. Current version 3.3.10, released periodically with bug fixes and improvements.

pip install mailman

Common errors

error ImportError: No module named mailman ↓

cause mailman is not installed or not in Python path.

fix

pip install mailman

error ConfigurationError: No configuration file found. ↓

cause config.load() called without a valid path or MAILMAN_CONFIG not set.

fix

Set MAILMAN_CONFIG environment variable or pass path existing cfg file.

error KeyError: 'my-list' ↓

cause The list does not exist in the database.

fix

Create the list first via REST API or mailman.core.initialize.

Warnings

breaking Mailman 3.x is a complete rewrite from 2.x; APIs are not compatible. Do not expect Mailman 2.x patterns to work. ↓

fix Use the new REST API and library interfaces. See documentation for migration.

deprecated Direct database manipulation is deprecated; use the REST API or the library's public interfaces. ↓

fix Use mailman.client (REST client) or mailman.interfaces for operations.

gotcha Configuration must be loaded before accessing any components. Forgetting config.load() will raise errors. ↓

fix Always call config.load('/path/to/mailman.cfg') early in your script.

Imports

mailman
wrong
```
from mailman import core
```
correct
```
import mailman
```
Top-level import is sufficient; direct submodule imports may break if internal structure changes.
IMailingList
wrong
```
from mailman.model import MailingList
```
correct
```
from mailman.interfaces import IMailingList
```
IMailingList is the interface; model classes are internal and not part of the public API.

Quickstart

Initialize Mailman from config and access a mailing list.

import os
from mailman.config import config

# Initialize with a configuration file
config.load(os.environ.get('MAILMAN_CONFIG', '/etc/mailman.cfg'))

# Get a mailing list instance (example)
from mailman.interfaces import IMailingList
# Assuming a list exists
list_name = 'my-list'
mlist = config.db.list_store.get(list_name)
print(f'List: {mlist.fqdn_listname}')