"""Base email backend class."""

class BaseEmailBackend(object):

    """

    Base class for email backend implementations.

    Subclasses must at least overwrite send_messages().

    """

    def __init__(self, fail_silently=False, **kwargs):

        self.fail_silently = fail_silently

    def open(self):

        """Open a network connection.

        This method can be overwritten by backend implementations to

        open a network connection.

        It's up to the backend implementation to track the status of

        a network connection if it's needed by the backend.

        This method can be called by applications to force a single

        network connection to be used when sending mails. See the

        send_messages() method of the SMTP backend for a reference

        implementation.

        The default implementation does nothing.

        """

        pass

    def close(self):

        """Close a network connection."""

        pass

    def send_messages(self, email_messages):

        """

        Sends one or more EmailMessage objects and returns the number of email

        messages sent.

        """

        raise NotImplementedError