repoze.sendmail¶

repoze.sendmail allows coupling the sending of email messages with a transaction, using the Zope transaction manager. This allows messages to only be sent out when and if a transaction is committed, preventing users from receiving notifications about events which may not have completed successfully. Messages may be sent directly or stored in a queue for later sending. The queued mail approach is the more common and recommended path. For convenience, the package includes a console application which can flush the queue, sending the messages that it finds.

repoze.sendmail is a fork of zope.sendmail. Functionality that was specific to running in a Zope context has been removed, making this version more generally useful to users of other frameworks.

Note that repoze.sendmail works only under Python 2.6+ and Python 3.2+.

Delivering Mail Messages from Application Code¶

Messages are sent by means of a Delivery object. repoze.sendmail include Two delivery implementations:

repoze.sendmail.delivery.QueuedMailDelivery
repoze.sendmail.delivery.DirectMailDelivery

A delivery implements the interface defined by repoze.sendmail.interfaces.IDelivery. That interface defines a single send method:

def send(fromaddr, toaddrs, message):
    """ Sends message on transaction commit. """

fromaddr is the address of the sender of the message.
toaddrs is a list of email addresses for recipients of the message.
message must be an instance of email.message.Message and is the actual message which will be sent.

Delivery via a Mail Queue¶

To create a queued delivery:

from email.message import Message
from repoze.sendmail.delivery import QueuedMailDelivery

message = Message()
message['From'] = 'Chris <chris@example.com>'
message['To'] = 'Paul <paul@example.com>, Tres <tres@example.com>'
message['Subject'] = "repoze.sendmail is a useful package"
message.set_payload("The subject line says it all.")

delivery = QueuedMailDelivery('path/to/queue')
delivery.send('chris@example.com', ['paul@example.com', 'tres@example.com'],
              message)

The message will be added to the maildir queue in ‘path/to/queue’ when and if the current transaction is committed successsfully.

repoze.sendmail includes a console app utility for sending queued messages:

$ bin/qp path/to/queue

This will attempt to use an SMTP server at localhost to send any messages found in the queue. To see all options available:

$ bin/qp --help

The QueueProcessor used by the console utility can also be called from Python:

qp = QueueProcessor(mailer, queue_path, ignore_transient=True)
qp.send_messages()

The ignore_transient parameter, when True, will cause the queue processor to ignore transient errors (any error code not between 500 and 599). This is useful when monitoring systems are used, to prevent filling the error reports with temporary errors.

Direct SMTP Delivery¶

Direct delivery (using the SMTP protocol) can also be used:

from repoze.sendmail.delivery import DirectMailDelivery
from repoze.sendmail.mailer import SMTPMailer

mailer = SMTPMailer()  # Uses localhost, port 25 be default.
delivery = DirectMailDelivery(mailer)
delivery.send('chris@example.com', ['paul@example.com', 'tres@example.com'],
              message)

Delivery via the sendmail Command¶

If you are on a Unix/BSD machine and prefer to use the standard unix sendmail interface ( which is likely provided by exim, postfix or qmail ) via a binary at ‘/usr/sbin/sendmail’ you can simply opt to use the following classes :

mailer = SendmailMailer()
delivery = DirectMailDelivery(mailer)

you may also customize this delivery with the location of another binary:

mailer = SendmailMailer(sendmail_app='/usr/local/bin/sendmail')

Transaction Integration¶

repoze.sendmail hooks into the Zope transaction manager and only sends messages on transaction commit. If you are using a framework which does not use transactions by default, you will need to begin and commit a transaction of your own in order for mail to be sent:

import transaction
transaction.manager.begin()
try:
    my_code_here()
    transaction.manager.commit()
except e:
    transaction.manager.abort()
    raise e