smtpd-tls

An extension to the python 2.x smtpd standard library implementing implicit/explicit (STARTTLS) SSL/TLS support

• added STARTTLS handling
• added implicit tls

just pass a configured ssl.context (certs, keys, protocols, auth, ...) to smtpd-tls.SMTPServer()

original smtpd pydoc: https://docs.python.org/2/library/smtpd.html

Requires Python 2.7 or higher

Install

from pip

pip install smtpd-tls

from source

python setup.py install

verify:

#> python -c "import smtpd_tls; print smtpd_tls"
#> python -m smtpd_tls --help

Example

STARTTLS via smtp port 25:

#> python -m smtpd_tls --debug -c DebuggingServer --starttls --keyfile=../server.pem 0.0.0.0:25
DebuggingServer started at Thu Feb  4 16:57:06 2016
        Local addr: ('0.0.0.0', 25)
        Remote addr:('mail.somehost.com', 25)
        TLS Mode: explicit (plaintext until STARTTLS)
        TLS Context: <ssl.SSLContext object at 0x7f8fd8adbbb0>
Incoming connection from ('192.168.139.1', 39983)
Peer: ('192.168.139.1', 39983)
Data: 'ehlo [192.168.139.1]'
Data: 'STARTTLS'
Peer: ('192.168.139.1', 39983) - negotiated TLS: ('ECDHE-RSA-AES256-GCM-SHA384', 'TLSv1/SSLv3', 256)
Data: 'ehlo [192.168.139.1]'
Data: 'mail FROM:<sender@example.com>'
===> MAIL FROM:<sender@example.com>
sender: sender@example.com
Data: 'rcpt TO:<user@example.com>'
===> RCPT TO:<user@example.com>
recips: ['user@example.com']
Data: 'data'
Data: "From: sender@example.com\r\nTo: user@example.com\r\nSubject: Hello!\r\n\r\nThis message was sent with Python's smtplib."
---------- MESSAGE FOLLOWS ----------
From: sender@example.com
To: user@example.com
Subject: Hello!
X-Peer: 192.168.139.1

This message was sent with Python's smtplib.
------------ END MESSAGE ------------
Data: 'quit'

Implicit TLS via smtp port 465:

#> python -m smtpd_tls --debug -c DebuggingServer --tls --keyfile=../server.pem 0.0.0.0:465
DebuggingServer started at Thu Feb  4 17:00:53 2016
        Local addr: ('0.0.0.0', 465)
        Remote addr:('mail.somehost.com', 25)
        TLS Mode: implicit (encrypted from the beginning)
        TLS Context: <ssl.SSLContext object at 0x7fee6ec36bb0>
Incoming connection from ('192.168.139.1', 40028)
Peer: ('192.168.139.1', 40028) - negotiated TLS: ('ECDHE-RSA-AES256-GCM-SHA384', 'TLSv1/SSLv3', 256)
Peer: ('192.168.139.1', 40028)
Data: 'ehlo [192.168.139.1]'
Data: 'mail FROM:<sender@example.com>'
===> MAIL FROM:<sender@example.com>
sender: sender@example.com
Data: 'rcpt TO:<user@example.com>'
===> RCPT TO:<user@example.com>
recips: ['user@example.com']
Data: 'data'
Data: "From: sender@example.com\r\nTo: user@example.com\r\nSubject: Hello!\r\n\r\nThis message was sent with Python's smtplib."
---------- MESSAGE FOLLOWS ----------
From: sender@example.com
To: user@example.com
Subject: Hello!
X-Peer: 192.168.139.1

This message was sent with Python's smtplib.
------------ END MESSAGE ------------
Data: 'quit'