nullsmtpd is a fake SMTP server (written in python) which can be used for development. The server catches incoming mail,
writes them to a file, and doesn't actually send it out to the intended recipients. All emails are saved to a directory
(defaults to /var/log/nullsmtpd, but can be changed via flag) where each email address sent to gets its own folder
and then emails are stored in that folder named {sender}.{time}.msg. This is useful for debugging applications
where you don't want a GUI (as you're running a headless VM say), but still actually need to see the messages that
were sent in the system, without having to worry about things getting bounced or whatever.
Generally, you'd probably want to install this instead of something like sendmail or some other package that would handle sending mail from your server.
nullsmtpd relies on Python 3.5+ and aiosmtpd. Recommended to also have pip for installation.
Recommended Installation is through PyPi:
pip install nullsmtpd
Or if you've cloned the repository:
python3 setup.py install
usage: nullsmtpd [-h] [--no-fork] [-H HOST] [-P PORT] [--mail-dir MAIL_DIR]
[-v]
optional arguments:
-h, --help show this help message and exit
--no-fork Don't fork and run nullsmtpd as a daemon. Additionally,
this willprint all log messages to stdout/stderr and
all emails to stdout.
-H HOST, --host HOST Host to listen on
-P PORT, --port PORT Port to listen on
--mail-dir MAIL_DIR Location to write logs and emails (defaults to
~/.nullsmtpd)
-v, --version show program's version number and exit
By default, you will need to use sudo as the server wants to bind itself to localhost and port 22.
However, if you use a different port, then it will not require using sudo. However, note, that if the current running
user of the script does not have access to create a directory/file within /var/log or /var/log/nullsmtpd, then
no emails will be written to file, but just through the console.
If the mail directory is writeable to, then you should have the following directory structure:
nullsmtpd.log [email protected]/ [email protected] [email protected] [email protected] [email protected]/ [email protected]
where nullsmtpd.log a log file for the system, and then each folder represents a person's "inbox" and inside
are messages from someone at a given timestamp (seconds from epoch).