Set new Melange version number to 0-5-20090825 in app.yaml.template.
"""
Tools for sending email.
"""
import mimetypes
import os
import smtplib
import socket
import time
import random
from email import Charset, Encoders
from email.MIMEText import MIMEText
from email.MIMEMultipart import MIMEMultipart
from email.MIMEBase import MIMEBase
from email.Header import Header
from email.Utils import formatdate, parseaddr, formataddr
from django.conf import settings
from django.utils.encoding import smart_str, force_unicode
# Don't BASE64-encode UTF-8 messages so that we avoid unwanted attention from
# some spam filters.
Charset.add_charset('utf-8', Charset.SHORTEST, Charset.QP, 'utf-8')
# Default MIME type to use on attachments (if it is not explicitly given
# and cannot be guessed).
DEFAULT_ATTACHMENT_MIME_TYPE = 'application/octet-stream'
# Cache the hostname, but do it lazily: socket.getfqdn() can take a couple of
# seconds, which slows down the restart of the server.
class CachedDnsName(object):
def __str__(self):
return self.get_fqdn()
def get_fqdn(self):
if not hasattr(self, '_fqdn'):
self._fqdn = socket.getfqdn()
return self._fqdn
DNS_NAME = CachedDnsName()
# Copied from Python standard library, with the following modifications:
# * Used cached hostname for performance.
# * Added try/except to support lack of getpid() in Jython (#5496).
def make_msgid(idstring=None):
"""Returns a string suitable for RFC 2822 compliant Message-ID, e.g:
<20020201195627.33539.96671@nightshade.la.mastaler.com>
Optional idstring if given is a string used to strengthen the
uniqueness of the message id.
"""
timeval = time.time()
utcdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(timeval))
try:
pid = os.getpid()
except AttributeError:
# No getpid() in Jython, for example.
pid = 1
randint = random.randrange(100000)
if idstring is None:
idstring = ''
else:
idstring = '.' + idstring
idhost = DNS_NAME
msgid = '<%s.%s.%s%s@%s>' % (utcdate, pid, randint, idstring, idhost)
return msgid
class BadHeaderError(ValueError):
pass
def forbid_multi_line_headers(name, val):
"""Forbids multi-line headers, to prevent header injection."""
val = force_unicode(val)
if '\n' in val or '\r' in val:
raise BadHeaderError("Header values can't contain newlines (got %r for header %r)" % (val, name))
try:
val = val.encode('ascii')
except UnicodeEncodeError:
if name.lower() in ('to', 'from', 'cc'):
result = []
for item in val.split(', '):
nm, addr = parseaddr(item)
nm = str(Header(nm, settings.DEFAULT_CHARSET))
result.append(formataddr((nm, str(addr))))
val = ', '.join(result)
else:
val = Header(val, settings.DEFAULT_CHARSET)
else:
if name.lower() == 'subject':
val = Header(val)
return name, val
class SafeMIMEText(MIMEText):
def __setitem__(self, name, val):
name, val = forbid_multi_line_headers(name, val)
MIMEText.__setitem__(self, name, val)
class SafeMIMEMultipart(MIMEMultipart):
def __setitem__(self, name, val):
name, val = forbid_multi_line_headers(name, val)
MIMEMultipart.__setitem__(self, name, val)
class SMTPConnection(object):
"""
A wrapper that manages the SMTP network connection.
"""
def __init__(self, host=None, port=None, username=None, password=None,
use_tls=None, fail_silently=False):
self.host = host or settings.EMAIL_HOST
self.port = port or settings.EMAIL_PORT
self.username = username or settings.EMAIL_HOST_USER
self.password = password or settings.EMAIL_HOST_PASSWORD
self.use_tls = (use_tls is not None) and use_tls or settings.EMAIL_USE_TLS
self.fail_silently = fail_silently
self.connection = None
def open(self):
"""
Ensures we have a connection to the email server. Returns whether or
not a new connection was required (True or False).
"""
if self.connection:
# Nothing to do if the connection is already open.
return False
try:
# If local_hostname is not specified, socket.getfqdn() gets used.
# For performance, we use the cached FQDN for local_hostname.
self.connection = smtplib.SMTP(self.host, self.port,
local_hostname=DNS_NAME.get_fqdn())
if self.use_tls:
self.connection.ehlo()
self.connection.starttls()
self.connection.ehlo()
if self.username and self.password:
self.connection.login(self.username, self.password)
return True
except:
if not self.fail_silently:
raise
def close(self):
"""Closes the connection to the email server."""
try:
try:
self.connection.quit()
except socket.sslerror:
# This happens when calling quit() on a TLS connection
# sometimes.
self.connection.close()
except:
if self.fail_silently:
return
raise
finally:
self.connection = None
def send_messages(self, email_messages):
"""
Sends one or more EmailMessage objects and returns the number of email
messages sent.
"""
if not email_messages:
return
new_conn_created = self.open()
if not self.connection:
# We failed silently on open(). Trying to send would be pointless.
return
num_sent = 0
for message in email_messages:
sent = self._send(message)
if sent:
num_sent += 1
if new_conn_created:
self.close()
return num_sent
def _send(self, email_message):
"""A helper method that does the actual sending."""
if not email_message.recipients():
return False
try:
self.connection.sendmail(email_message.from_email,
email_message.recipients(),
email_message.message().as_string())
except:
if not self.fail_silently:
raise
return False
return True
class EmailMessage(object):
"""
A container for email information.
"""
content_subtype = 'plain'
multipart_subtype = 'mixed'
encoding = None # None => use settings default
def __init__(self, subject='', body='', from_email=None, to=None, bcc=None,
connection=None, attachments=None, headers=None):
"""
Initialize a single email message (which can be sent to multiple
recipients).
All strings used to create the message can be unicode strings (or UTF-8
bytestrings). The SafeMIMEText class will handle any necessary encoding
conversions.
"""
if to:
assert not isinstance(to, basestring), '"to" argument must be a list or tuple'
self.to = list(to)
else:
self.to = []
if bcc:
assert not isinstance(bcc, basestring), '"bcc" argument must be a list or tuple'
self.bcc = list(bcc)
else:
self.bcc = []
self.from_email = from_email or settings.DEFAULT_FROM_EMAIL
self.subject = subject
self.body = body
self.attachments = attachments or []
self.extra_headers = headers or {}
self.connection = connection
def get_connection(self, fail_silently=False):
if not self.connection:
self.connection = SMTPConnection(fail_silently=fail_silently)
return self.connection
def message(self):
encoding = self.encoding or settings.DEFAULT_CHARSET
msg = SafeMIMEText(smart_str(self.body, settings.DEFAULT_CHARSET),
self.content_subtype, encoding)
if self.attachments:
body_msg = msg
msg = SafeMIMEMultipart(_subtype=self.multipart_subtype)
if self.body:
msg.attach(body_msg)
for attachment in self.attachments:
if isinstance(attachment, MIMEBase):
msg.attach(attachment)
else:
msg.attach(self._create_attachment(*attachment))
msg['Subject'] = self.subject
msg['From'] = self.from_email
msg['To'] = ', '.join(self.to)
# Email header names are case-insensitive (RFC 2045), so we have to
# accommodate that when doing comparisons.
header_names = [key.lower() for key in self.extra_headers]
if 'date' not in header_names:
msg['Date'] = formatdate()
if 'message-id' not in header_names:
msg['Message-ID'] = make_msgid()
for name, value in self.extra_headers.items():
msg[name] = value
return msg
def recipients(self):
"""
Returns a list of all recipients of the email (includes direct
addressees as well as Bcc entries).
"""
return self.to + self.bcc
def send(self, fail_silently=False):
"""Sends the email message."""
return self.get_connection(fail_silently).send_messages([self])
def attach(self, filename=None, content=None, mimetype=None):
"""
Attaches a file with the given filename and content. The filename can
be omitted (useful for multipart/alternative messages) and the mimetype
is guessed, if not provided.
If the first parameter is a MIMEBase subclass it is inserted directly
into the resulting message attachments.
"""
if isinstance(filename, MIMEBase):
assert content == mimetype == None
self.attachments.append(filename)
else:
assert content is not None
self.attachments.append((filename, content, mimetype))
def attach_file(self, path, mimetype=None):
"""Attaches a file from the filesystem."""
filename = os.path.basename(path)
content = open(path, 'rb').read()
self.attach(filename, content, mimetype)
def _create_attachment(self, filename, content, mimetype=None):
"""
Converts the filename, content, mimetype triple into a MIME attachment
object.
"""
if mimetype is None:
mimetype, _ = mimetypes.guess_type(filename)
if mimetype is None:
mimetype = DEFAULT_ATTACHMENT_MIME_TYPE
basetype, subtype = mimetype.split('/', 1)
if basetype == 'text':
attachment = SafeMIMEText(smart_str(content,
settings.DEFAULT_CHARSET), subtype, settings.DEFAULT_CHARSET)
else:
# Encode non-text attachments with base64.
attachment = MIMEBase(basetype, subtype)
attachment.set_payload(content)
Encoders.encode_base64(attachment)
if filename:
attachment.add_header('Content-Disposition', 'attachment',
filename=filename)
return attachment
class EmailMultiAlternatives(EmailMessage):
"""
A version of EmailMessage that makes it easy to send multipart/alternative
messages. For example, including text and HTML versions of the text is
made easier.
"""
multipart_subtype = 'alternative'
def attach_alternative(self, content, mimetype=None):
"""Attach an alternative content representation."""
self.attach(content=content, mimetype=mimetype)
def send_mail(subject, message, from_email, recipient_list,
fail_silently=False, auth_user=None, auth_password=None):
"""
Easy wrapper for sending a single message to a recipient list. All members
of the recipient list will see the other recipients in the 'To' field.
If auth_user is None, the EMAIL_HOST_USER setting is used.
If auth_password is None, the EMAIL_HOST_PASSWORD setting is used.
Note: The API for this method is frozen. New code wanting to extend the
functionality should use the EmailMessage class directly.
"""
connection = SMTPConnection(username=auth_user, password=auth_password,
fail_silently=fail_silently)
return EmailMessage(subject, message, from_email, recipient_list,
connection=connection).send()
def send_mass_mail(datatuple, fail_silently=False, auth_user=None,
auth_password=None):
"""
Given a datatuple of (subject, message, from_email, recipient_list), sends
each message to each recipient list. Returns the number of e-mails sent.
If from_email is None, the DEFAULT_FROM_EMAIL setting is used.
If auth_user and auth_password are set, they're used to log in.
If auth_user is None, the EMAIL_HOST_USER setting is used.
If auth_password is None, the EMAIL_HOST_PASSWORD setting is used.
Note: The API for this method is frozen. New code wanting to extend the
functionality should use the EmailMessage class directly.
"""
connection = SMTPConnection(username=auth_user, password=auth_password,
fail_silently=fail_silently)
messages = [EmailMessage(subject, message, sender, recipient)
for subject, message, sender, recipient in datatuple]
return connection.send_messages(messages)
def mail_admins(subject, message, fail_silently=False):
"""Sends a message to the admins, as defined by the ADMINS setting."""
EmailMessage(settings.EMAIL_SUBJECT_PREFIX + subject, message,
settings.SERVER_EMAIL, [a[1] for a in settings.ADMINS]
).send(fail_silently=fail_silently)
def mail_managers(subject, message, fail_silently=False):
"""Sends a message to the managers, as defined by the MANAGERS setting."""
EmailMessage(settings.EMAIL_SUBJECT_PREFIX + subject, message,
settings.SERVER_EMAIL, [a[1] for a in settings.MANAGERS]
).send(fail_silently=fail_silently)