async function sendEmail(agent, settings, email_recipient_filter) {
    // Prepare a post and email model
    const completedPromise = jobManager.awaitCompletion('batch-sending-service-job');
    const emailModel = await createPublishedPostEmail(agent, settings, email_recipient_filter);

    assert.ok(emailModel.get('subject'));
    assert.ok(emailModel.get('from'));
    assert.equal(emailModel.get('source_type'), settings && settings.mobiledoc ? 'mobiledoc' : 'lexical');

    // Await sending job
    await completedPromise;

    await emailModel.refresh();
    assert.equal(emailModel.get('status'), 'submitted');

    lastEmailModel = emailModel;

    // Get the email that was sent
    return {emailModel, ...(await getLastEmail())};
}
Try sending an email, and assert that it succeeded
@returns {Promise<SendEmail>}