Issue #3264279 by AdamPS: Send email as plaintext

  type: mapping

  label: 'Inline CSS'

symfony_mailer.email_adjuster_plugin.mailer_plain_only:

  type: mapping

  label: 'Plain text only'

symfony_mailer.email_adjuster_plugin.mailer_url_to_absolute:

  type: mapping

  label: 'URL to absolute'

<?php

namespace Drupal\symfony_mailer\Plugin\EmailAdjuster;

use Drupal\symfony_mailer\Processor\EmailAdjusterBase;

use Drupal\symfony_mailer\EmailInterface;

/**

 * Defines the Plain text only Email Adjuster.

 *

 * @EmailAdjuster(

 *   id = "mailer_plain_only",

 *   label = @Translation("Plain text only"),

 *   description = @Translation("Sends email as plain text only."),

 *   weight = 810,

 * )

 */

class PlainOnlyEmailAdjuster extends EmailAdjusterBase {

  /**

   * {@inheritdoc}

   */

  public function postRender(EmailInterface $email) {

    $email->setHtmlBody(NULL);

  }

}