Skip to main content

Full-featured e-mailing system: flexible, slim and sexy

Project description

Build Status


Full-featured e-mailing system: flexible, slim and sexy.

  • Unicode
  • Easy attachments
  • Inline images
  • E-Mail templates
  • Tools for unit-tests
  • Made perfect once and for all. Simple and cute :)

Here’a a full example:

from mailem import Message, Postman, Attachment, ImageAttachment
from mailem.connection import SMTPConnection

# Create the message
messages = [
    # Message with attachments
        u"Mail'em test",
        u"<b>yeah baby, it works!</b>",
        attachments = [
            Attachment(u'test.txt', open('test.txt').read())
    # Message with inline images (!)
        u"Mail'em test with inline images",
        u"Cute: <img src='cid:cute.jpg' />",  # cid:<filename>
        attachments = [
            ImageAttachment('cute.jpg', open('cute.jpg').read(), 'inline')

# Initialize a postman with SMTP connection to GMail
postman = Postman('',
                      '', 587,
                      '', 'pass',

# Send everything we have
with postman.connect() as c:
    map(c.sendmail, messages)

Also see Template.

Table of Contents

  • Sending Messages
    • Message
      • Attachment
      • ImageAttachment
    • Postman
      • Postman.connect
      • Postman.loopback
    • Connection
      • SMTPConnection
      • LoopbackConnection
  • Templating
    • Template
      • Template.set_renderer
      • Template.defaults
      • Template.from_directory
    • TemplateRegistry
      • TemplateRegistry.add
      • TemplateRegistry.set_renderer
      • TemplateRegistry.defaults
      • TemplateRegistry.get
      • TemplateRegistry.from_directory

Sending Messages


Message(recipients, subject, html=None,
        text=None, sender=None, cc=None,
        bcc=None, attachments=None,
        reply_to=None, date=None, headers=None)

Construct a Message object.


  • Full unicode support, and Unicode is the default
  • You can provide html or text contents. If both are specified – the message will have an ‘alternative’ container, so the user will receive both HTML and plaintext. The client will choose which one to display.
  • E-Mail addresses, such as recipients and sender, can be specified in one of the following formats:
    • '': Just an e-mail address
    • ('', u'Honored User'): email address with name


  • recipients: List of recipients
  • subject: Message subject
  • html: Message body, HTML
  • text: Message body, Text
  • sender: Sender e-mail address. If not set explicitly, the default will be used on send
  • cc: CC list
  • bcc: BCC list
  • attachments: List of attachments
  • reply_to: Reply-to address
  • date: Send date
  • headers: Additional headers


Attachment(filename, data,
           disposition='attachment', headers=None)

File attachment information.

This can be provided to the `Message <#message>`__ object on construction.

  • filename: Filename of attachment
  • data: Taw file data
  • content_type: File mimetype
  • disposition: Content-Disposition: ‘attachment’, ‘inline’, …
  • headers: Additional headers for the attachment


ImageAttachment(filename, data,
                disposition='attachment', headers=None)

Image attachment.

  • It guesses the Content-Type from the data stream

  • Supports ‘inline’ images: images embedded in the email. Useful for templates.

    Once an ‘inline’ image is created, its filename is used for ‘Content-ID’, which allows to reference it in the HTML body:

    from mailem import Message, Attachment, ImageAttachment
    msg = Message(
        '<img src="cid:flowers.jpg" />',  # Referenced with "cid:<filename>"
            ImageAttachment('flowers.jpg', open('flowers.jpg').read(), 'inline')


  • filename: Image attachment filename. Will also become ‘Content-ID’ when inlined.
  • data: The raw file data


Postman(sender, connection)

Postman is the object you use to send messages through a configured Connection object.


from mailem import Message, Postman
from mailem.connection import SMTPConnection

# Construct the message
msg = Message(
    u"Mail'em test",
    u"<b>yeah baby, it works!</b>"

# Create the postman (see SMTPConnection)
postman = Postman('',

# Connect, and send the message
with postman.connect() as c:
  • sender: Default sender: e-mail or (name, email). Is used for messages which do not specify the sender address explicitly.
  • connection: Connection object to use. See below.



Get connected Postman context manager.

Returns: mailem.postman.ConnectedPostman



Get a context manager which installs a LoopbackConnection on this postman.

This allows you to record outgoing messages by mocking a Postman. See `LoopbackConnection <#loopbackconnection>`__.

Returns: MockedPostman Context manager which loops back outgoing messages


Connection object represents a connection to a service which can send e-mail messages for us.


SMTPConnection(host, port, username,
               password, local_hostname=None,
               ssl=False, tls=False)

SMTP connection.

See smtplib for the list of exceptions that may occur.


from mailem import Postman
from mailem.connection import SMTPConnection

postman = Postman('',
                  '', 587,
                  '', 'pass',

with postman.connect() as c:


  • host: SMTP server hostname
  • port: SMTP server port number.
  • username: User name to authenticate with
  • password: Password
  • local_hostname: FQDN of the local host for the HELO/EHLO command. When None, is detected automatically.
  • ssl: Use SSL protocol?
  • tls: Use TLS handshake?



Loopback connection allows to record all outgoing messages instead of sending them.

You can install it manually:

from mailem import Postman
from mailem.connection import LoopbackConnection

lo = LoopbackConnection()
postman = Postman('', lo)
#... send
messages = lo.get_messages()

or you can mock an existing Postman with loopback() helper:

from mailem import Postman
from mailem.connection import SMTPConnection

postman = Postman('',

with postman.loopback() as lo:
    # Send
    with postman.connect() as c:  # mocked!

# Get
sent_messages = lo.get_messages()

Loopback can be installed multiple times, and only top-level loopback will catch the messages:

with postman.loopback() as lo1:
    with postman.loopback() as lo2:
        with postman.connect() as c:

len(lo1)  #-> 0
len(lo2)  #-> 1

Also note that LoopbackConnection subclasses list, so all list methods, including iteration, is available.



Template(subject=None, html=None,
         text=None, attachments=None,

A templated e-mail.

By default, the Template uses Python’s Template renderer, which allows simple PHP-style substitution, but this can be overridden using set_renderer().

First, a template is defined:

from mailem import Attachment
from mailem.template import Template

signup = Template('Congrats $user, you've signed up!',
    'Welcome to our website!<br><img src="cid:logo.jpg" /> -- $domain',
        Attachment('logo.jpg', open('logo.jpg').read(), 'inline'))
    defaults={'domain': 'localhost'}  # default template values

Now, having the template, you render it to a `Message <#message>`__ by calling it:

message = signup([''], dict(user='Honored User',))

Ready for sending! :)

  • subject: Message subject template
  • html: HTML message template, if any
  • text: Text message template, if any
  • attachments: Attachments for the template. Most probably, inline elements.
  • defaults: Default template values, if required. The user can override these later.


set_renderer(Renderer, **kwargs)

Set renderer to be used with this template.

A Renderer is any class that can be constructed with a template string argument, and called with template values dict to render it.

When no renderer was explicitly set, it defaults to PythonTemplateRenderer.

See mailem/template/ it’s easy to implement renderers with custom behavior!

  • Renderer: Renderer class.
  • **kwargs: Additional arguments to renderer, if supported



Set default values.

New values will overwrite the previous.

  • values: Default template values

__call__(recipients, values, **kwargs)

Create a Message object using the template values.

  • recipients: Message recipients list
  • values: Dictionary with template values
  • **kwargs: keyword arguments for the `Message <#message>`__ constructor

Returns: Message The rendered Message object



Convenience class method to import a directory as a template:

  • subject.txt is the subject string template

  • index.htm is the HTML template

  • index.txt is the plaintext template

  • All files matching the ‘i-(*)’ format are attached as ‘inline’, and hence can be referenced in the template:

    E.g. file ‘i-flower.jpg’ can be inlined as <img src="cid:flower.jpg" />.

  • All other files are just attachments.


signup = Template.from_directory('templates/signup/')
  • path: Path to the directory

  • subject_name: Subject template filename

  • html_name: Html template filename

  • text_name: Plaintext template filename

  • inline_rex: Regular expression to match files that should be inlined.

    If the RegExp defines capture groups, group $1 will be used as the fact filename.

Returns: Template Template



E-Mail template registry.

Simply contains all your templates and allows to render these by name. Useful if you have multiple templates in your app and want to have them prepared.

Initially, the registry is empty, and you add `Template <#template>`__ objects one by one:

from mailem.template import Template, TemplateRegistry

templates = TemplateRegistry()
templates.add('signup', Template(
            'Congrats $user, you've signed up!',
           'Welcome to our website!<br> -- $domain',
templates.defaults(dict(domain=''))  # set defaults on all templates

Alternatively, you can use `TemplateRegistry.from_directory() <#templateregistryfrom_directory>`__ to load templates from filesystem.

Now, to render a template, you `get() <#templateregistryget>`__ it by name:

msg = templates.get('signup')([''], dict(user='Honored User',))


add(name, template)

Register a template

  • template: Template object

Returns: mailem.template.Template The added template (in case you want to set something on it)


set_renderer(renderer, **kwargs)

Set renderer to be used with all templates.

Can be called both before adding templates and after.

  • renderer: Renderer class to use
  • **kwargs: Additional arguments for the renderer



Set default values on all templates.

New values will overwrite the previous.

Can be called both before adding templates and after.

  • values: Default template values



Get a Template by name

  • name: Template name

Returns: mailem.template.Template


from_directory(path, **kwargs)

Convenience method to construct a template registry with a directory where each template is in a subdirectory

Returns: mailem.template.registry.TemplateRegistry

Project details

Release history Release notifications

This version
History Node


History Node


History Node


History Node


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
mailem-0.0.3_1-py2-none-any.whl (24.0 kB) Copy SHA256 hash SHA256 Wheel 2.7 Aug 15, 2014
mailem-0.0.3-1.tar.gz (19.8 kB) Copy SHA256 hash SHA256 Source None Aug 15, 2014

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging CloudAMQP CloudAMQP RabbitMQ AWS AWS Cloud computing Fastly Fastly CDN DigiCert DigiCert EV certificate StatusPage StatusPage Status page