dsmtpd 1.1

Simple SMTP Server for debugging

dsmptd: A debugger SMTP server for Humans

dsmtpd is a small tool to help the developer without an smtp server

Usage

$ dsmtpd -p 1025 -i 127.0.0.1
2013-01-13 14:00:07,346 INFO: Starting SMTP server at 127.0.0.1:1025

Installation

For the installation, we recommend to use a virtualenv, it’s the easy way if you want to discover this package:

virtualenv ~/.envs/dsmtpd
source ~/.envs/dsmtpd/bin/activate

pip install dsmtpd

Documentation

Execute dsmtpd with the –help flag and you will get the usage of this command:

dsmtpd --help

There are three options:

• -p You specify the port of dsmtpd (default is 1025)

• -i You specify the network interface (default is loopback, 127.0.0.1)

• -d You specify a Maildir directory to save the incoming emails

Use it

Here is a small example:

dsmtpd

swaks --from [e-mail] --to [e-mail]  --server localhost --port 1025

Exit Codes

dsmtpd uses specific exit codes to indicate the result of its execution.

Code	Meaning	Example
0	Success	Normal shutdown (e.g. user pressed Ctrl+C) or clean termination.
2	Invalid Maildir directory	The given path exists but does not contain the required subfolders: tmp, new, and cur.

Contributing

git clone git://github.com/matrixise/dsmtpd.git

Copyright 2013 (c) by Stephane Wirtel

dsmtpd Changelog

Here you can see the full list of changes between each dsmtpd release.

Version 1.1

Released on September 13th 2025.

• Lower Python version requirement from 3.12 to 3.10 (#17)

• Fix crash when directory exists but is not yet a valid Maildir with proper validation and repair functionality (#18)

• Add exit codes documentation to README

• Code formatting improvements with ruff

Version 1.0

Release on May 20th 2025.

• Migration to aiosmtpd to Support Python >= 3.12 (#11, patch by Sebastian Wagner)

• Add minimal tests for maildir check and importability

• Add systemd service file (by Sebastian Wagner)

Version 0.3

Release on May 26th 2021.

• Maildir capture: added early check (patch by Bernhard E. Reiter)

• Remove the support of Docopt

• Remove the support of Python 2.x (dead in 2020)

• Support Python 3.6+

• Improve the classifiers for PyPI

• Migrate to PEP 517

• Fix License into setup.py

• Add tests for the CLI using argparse instead of docopt

Version 0.2

Release on January 21st 2013.

• Allow to store the incoming emails in a maildir via the ‘-d’ argument

Version 0.1

Release on January 14th 2013.

• Implement a basic server

• Show the message in the log