This is simplest SMTP client you'll ever see. It's 100% synchronous...

Give your app an outbox easily:

from outbox import Outbox, Email, Attachment

# io.StringIO for Python 3 folks
from StringIO import StringIO

attachments = [
    Attachment('kittens.jpg', fileobj=open('ducks.jpg', 'rb')),
    Attachment('my-transient-file.bin', fileobj=StringIO('some raw data')),
]

outbox = Outbox(username='username', password='password',
        server='server', port=1234, mode='SSL')

outbox.send(Email(subject='my subject', body='some nice sentiment',
        recipients=['nathan@getoffmalawn.com']), attachments=attachments)

# html email with attachments
outbox.send(Email(subject='my subject', html_body='<b>SOME REALLY NICE SENTIMENT</b>',
        recipients=['nathan@getoffmalawn.com']), attachments=attachments)

This method will log in to the server each time send() is called.

Alternatively, you can use Outbox as a context manager:

with Outbox(username='username', password='password',
        server='server', port=1234, mode='SSL') as outbox:

    outbox.send(Email(subject='my subject', body='some nice sentiment',
            recipients=['nathan@getoffmalawn.com']), attachments=attachments)

    # html email with attachments
    outbox.send(Email(subject='my subject', html_body='<b>SOME REALLY NICE SENTIMENT</b>',
            recipients=['nathan@getoffmalawn.com']), attachments=attachments)

Using Outbox as a context manager has the added benefit of performing a single login to send all emails.

Installing Outbox.py is simple:

$ pip install outbox

0.1.8 (24th June 2014)

• Thanks to Hideaki Takahashi for teh following contributions!
• Added RFC2047 style encoding support.
• Much improved support for multipart messages.

0.1.7 (24th June 2014)

• Thanks to Hideaki Takahashi for submitting a MANIFEST, which allows outbox to be installed via pip again (broken in 0.1.6)

0.1.6 (24th June 2014)

• Added AnonymousOutbox, a class for connecting to servers that don't perform authentication.
• Fleshed out documentation for outbox.Email.
• Fixed a bug when using Python 3 (calling iteritems on a dict).
• Moved the project to Github.

0.1.5 (3rd March 2013)

• Thanks to Peter Naudus for the following contributions!
• Added debug argument to Outbox class, to switch smtplib's debugging.
• Added fields argument to Email class, to allow additional email fields to be set.
• Connection and disconnection are now exposed.
• Internal cleanup of some of the connection code.

0.1.4 (29th October 2012)

• Handle passing a single recipient as a string, instead of forcing the recipient to be a list.
• Handle utf8 email properly. Thanks, Zhang Mingyuan! I doubt I've covered every use case, so the charset to use can be passed in when constructing an Email.
• Added a sender_address method to the Outbox class, for when the username used for authentication isn't good enough.

0.1.3 (3rd July 2012)

• Made a few lines of code a bit easier to follow. No functional changes.
• Updated the license to actually hold copyright in my name, instead of Kenneth Reitz. Does this mean he owned copyright on the library up until now? Can I even change the license? I'm unsure.

0.1.2 (2nd June 2012)

• Made Outbox a context manager, so it can be used with the with statement. As noted in the example, this has the added benefit of performing a single login to send all emails, you should get better performance using a with statement.
• Removed raw and filepath arguments to Attachment. They were both begging to point to a file-like object, so that's what you have now - an argument called fileobj
• Fixed annoying encoding error when trying to send binary attachments.
• The Email object does not have a type argument anymore. Instead, there is body and html_body, so you can send an email with both html and plain-text bodies.

0.1.1 (27th May 2012)

• Initial release