Sending Mail

The mail API provides two ways to send an email message: the mail.send_mail() function and the EmailMessage class.

Sending is asynchronous: the mail.send_mail() function and the EmailMessage.send() method transmit the message data to the mail service, then return. The mail service queues the message, then attempts to send it, retrying if the destination mail server is unavailable. Errors and bounce messages are sent to the sender address for the email message.

Before you begin

You must register your sender emails as authorized senders. For more information, see who can send email.

Sending mail with mail.send_mail()

To send mail using the mail.send_mail() function, use the fields of the email message as parameters, including the sender, the recipients, the subject and the body of the message. For example:

    mail.send_mail(sender=sender_address,
                   to="Albert Johnson <[email protected]>",
                   subject="Your account has been approved",
                   body="""Dear Albert:

Your example.com account has been approved.  You can now visit
http://www.example.com/ and sign in using your Google Account to
access new features.

Please let us know if you have any questions.

The example.com Team
""")

Sending mail with EmailMessage

To send mail using objects with the EmailMessage class, pass the fields of the email message to the EmailMessage constructor and use attributes of the instance to update message.

The EmailMessage.send() method sends the email message represented by the instance's attributes. An application can re-use an EmailMessage instance by modifying attributes and calling the send() method again.

    message = mail.EmailMessage(
        sender=sender_address,
        subject="Your account has been approved")

    message.to = "Albert Johnson <[email protected]>"
    message.body = """Dear Albert:

Your example.com account has been approved.  You can now visit
http://www.example.com/ and sign in using your Google Account to
access new features.

Please let us know if you have any questions.

The example.com Team
"""
    message.send()

The following example demonstrates sending a message to confirm an email address:

class UserSignupHandler(webapp2.RequestHandler):
    """Serves the email address sign up form."""

    def post(self):
        user_address = self.request.get('email_address')

        if not mail.is_email_valid(user_address):
            self.get()  # Show the form again.
        else:
            confirmation_url = create_new_user_confirmation(user_address)
            sender_address = (
                'Example.com Support <{}@appspot.gserviceaccount.com>'.format(
                    app_identity.get_application_id()))
            subject = 'Confirm your registration'
            body = """Thank you for creating an account!
Please confirm your email address by clicking on the link below:

{}
""".format(confirmation_url)
            mail.send_mail(sender_address, user_address, subject, body)

Sending bulk mail

See the Bulk mail guidelines for considerations around sending bulk email.