smtp.install

<?php

/**
 * @file
 * The installation instructions for the SMTP Authentication Support.
 */

/**
 * Implements hook_uninstall().
 */
function smtp_uninstall() {
  $config = \Drupal::service('config.factory');
  $smtp_config = $config->getEditable('smtp.settings');

  // Restore previous mail system.
  $default_system_mail = 'php_mail';
  $mail_config = $config->getEditable('system.mail');
  $default_interface = (!$smtp_config->get('prev_mail_system')) ? $smtp_config->get('prev_mail_system') : $default_system_mail;
  $mail_config->set('interface.default', $default_interface)
    ->save();

  // Cleaning garbage.
  $smtp_config->delete();
}

/**
 * Add SMTP timeout configuration and change default to 30.
 */
function smtp_update_8001() {
  \Drupal::configFactory()->getEditable('smtp.settings')
    ->set('smtp_timeout', 30)
    ->save(TRUE);
}