diff --git a/core/modules/user/config/install/user.settings.yml b/core/modules/user/config/install/user.settings.yml
index ca46109..677add0 100644
--- a/core/modules/user/config/install/user.settings.yml
+++ b/core/modules/user/config/install/user.settings.yml
@@ -14,6 +14,5 @@ notify:
 register: visitors
 cancel_method: user_cancel_block
 password_reset_timeout: 86400
-mail_change_timeout: 86400
 password_strength: true
 langcode: en
diff --git a/core/modules/user/config/schema/user.schema.yml b/core/modules/user/config/schema/user.schema.yml
index 206a853..40a8475 100644
--- a/core/modules/user/config/schema/user.schema.yml
+++ b/core/modules/user/config/schema/user.schema.yml
@@ -53,9 +53,6 @@ user.settings:
     password_reset_timeout:
       type: integer
       label: 'Password reset timeout'
-    mail_change_timeout:
-      type: integer
-      label: 'Mail change timeout'
     password_strength:
       type: boolean
       label: 'Enable password strength indicator'
diff --git a/core/modules/user/src/AccountForm.php b/core/modules/user/src/AccountForm.php
index 9bbf9fb..9fdd4ce 100644
--- a/core/modules/user/src/AccountForm.php
+++ b/core/modules/user/src/AccountForm.php
@@ -396,7 +396,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
         _user_mail_notify('mail_change_notification', $account);
         // The user's mail address will be updated only after verification.
         $form_state->setValue('mail', $old_mail);
-        drupal_set_message($this->t('Your new email address needs to be validated. Further instructions have been sent to your new email address.'), 'warning');
+        drupal_set_message($this->t('Your updated email address needs to be validated. Further instructions have been sent to your new email address.'), 'warning');
       }
     }
 
diff --git a/core/modules/user/src/Controller/MailChangeController.php b/core/modules/user/src/Controller/MailChangeController.php
index 487c70d..14649e3 100644
--- a/core/modules/user/src/Controller/MailChangeController.php
+++ b/core/modules/user/src/Controller/MailChangeController.php
@@ -5,6 +5,7 @@
 use Drupal\Component\Utility\Crypt;
 use Drupal\Core\Access\AccessResult;
 use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\Site\Settings;
 use Drupal\Core\Url;
 use Drupal\user\UserInterface;
 
@@ -29,27 +30,28 @@ class MailChangeController extends ControllerBase {
    *   An HTTP response doing a redirect.
    */
   public function page(UserInterface $user, $new_mail, $timestamp, $hash) {
-    $timeout = $this->config('user.settings')->get('mail_change_timeout');
+    $timeout = Settings::get('mail_change_timeout', 86400);
     /** @var \Drupal\Core\Session\AccountProxyInterface $current_user */
     $current_user = $this->currentUser();
+    $request_time = \Drupal::time()->getRequestTime();
 
     // Other user is authenticated.
     if ($current_user->isAuthenticated() && $current_user->id() != $user->id()) {
       drupal_set_message($this->t('You are currently logged in as %user, and are attempting to confirm an email address change for another account. Please <a href=":logout">log out</a> and try using the link again.', ['%user' => $current_user->getAccountName(), ':logout' => Url::fromRoute('user.logout')->toString()]), 'error');
     }
     // The link has expired.
-    elseif (REQUEST_TIME - $timestamp > $timeout) {
+    elseif ($request_time - $timestamp > $timeout) {
       drupal_set_message($this->t('You have tried to use an email address change link that has expired. Please visit your account and change your email again.'), 'error');
     }
     // The link is valid.
-    elseif ($timestamp <= REQUEST_TIME && $timestamp >= $user->getLastLoginTime() && Crypt::hashEquals($hash, user_pass_rehash($user, $timestamp, $new_mail))) {
+    elseif ($timestamp <= $request_time && $timestamp >= $user->getLastLoginTime() && Crypt::hashEquals($hash, user_pass_rehash($user, $timestamp, $new_mail))) {
       // Save the new email but refresh also the last login time so that this
-      // mail change link get expired.
-      $user->setEmail($new_mail)->setLastLoginTime(REQUEST_TIME)->save();
+      // mail change link gets expired.
+      $user->setEmail($new_mail)->setLastLoginTime($request_time)->save();
       /** @var \Drupal\user\UserStorageInterface $user_storage */
       $user_storage = $this->entityTypeManager()->getStorage('user');
       $user_storage->updateLastLoginTimestamp($user);
-      // Reflect the changes in the session if the user is user is logged in.
+      // Reflect the changes in the session if the user is logged in.
       if ($current_user->isAuthenticated() && $current_user->id() == $user->id()) {
         $current_user->setAccount($user);
       }
@@ -96,7 +98,8 @@ public function access(UserInterface $user) {
    * @return \Drupal\Core\Url
    *   A unique url that provides a one-time email change confirmation.
    */
-  public static function getUrl(UserInterface $account, array $options = [], $timestamp = REQUEST_TIME, $hash = NULL) {
+  public static function getUrl(UserInterface $account, array $options = [], $timestamp = NULL, $hash = NULL) {
+    $timestamp = $timestamp ?: \Drupal::time()->getRequestTime();
     $langcode = isset($options['langcode']) ? $options['langcode'] : $account->getPreferredLangcode();
     $hash = empty($hash) ? user_pass_rehash($account, $timestamp) : $hash;
     $url_options = ['absolute' => TRUE, 'language' => \Drupal::service('language_manager')->getLanguage($langcode)];
diff --git a/core/modules/user/src/Tests/Update/UpdateMailChangeTest.php b/core/modules/user/src/Tests/Update/UpdateMailChangeTest.php
index 78d31dd..f5098e9 100644
--- a/core/modules/user/src/Tests/Update/UpdateMailChangeTest.php
+++ b/core/modules/user/src/Tests/Update/UpdateMailChangeTest.php
@@ -33,7 +33,6 @@ public function testMailChangeUpdate() {
     // Check that mail change notifications settings are not set.
     $this->assertNull($user_settings->get('notify.mail_change_notification'));
     $this->assertNull($user_settings->get('notify.mail_change_verification'));
-    $this->assertNull($user_settings->get('mail_change_timeout'));
 
     // Check that mail change configurations are not set.
     $this->assertNull($user_mail->get('mail_change_notification'));
@@ -47,8 +46,6 @@ public function testMailChangeUpdate() {
     // Check that mail change notifications were set to FALSE.
     $this->assertFalse($user_settings->get('notify.mail_change_notification'));
     $this->assertFalse($user_settings->get('notify.mail_change_verification'));
-    // Check that mail change timeout was set.
-    $this->assertIdentical($user_settings->get('mail_change_timeout'), 86400);
 
     $config = Yaml::parse(file_get_contents(__DIR__ . '/../../../config/install/user.mail.yml'));
 
diff --git a/core/modules/user/tests/src/Functional/UserMailChangeTest.php b/core/modules/user/tests/src/Functional/UserMailChangeTest.php
index cdc1b4e..1d376f5 100644
--- a/core/modules/user/tests/src/Functional/UserMailChangeTest.php
+++ b/core/modules/user/tests/src/Functional/UserMailChangeTest.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Tests\user\Functional;
 
+use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Core\Test\AssertMailTrait;
 use Drupal\Core\Url;
 use Drupal\Component\Utility\Unicode;
@@ -26,12 +27,20 @@ class UserMailChangeTest extends BrowserTestBase {
   protected $account;
 
   /**
+   * The date/time service.
+   *
+   * @var \Drupal\Component\Datetime\TimeInterface
+   */
+  protected $time;
+
+  /**
    * {@inheritdoc}
    */
   protected function setUp() {
     parent::setUp();
     // Create a user.
     $this->account = $this->drupalCreateUser();
+    $this->time = $this->container->get('datetime.time');
   }
 
   /**
@@ -46,10 +55,10 @@ public function testMailChange() {
       'mail' => $new_mail,
       'current_pass' => $this->account->pass_raw,
     ];
-    $this->drupalPostForm($this->account->toUrl('edit-form'), $edit, t('Save'));
+    $this->drupalPostForm($this->account->toUrl('edit-form'), $edit, 'Save');
 
     // Check that the validation status message has been displayed.
-    $this->assertSession()->pageTextContains(t('Your new email address needs to be validated. Further instructions have been sent to your new email address.'));
+    $this->assertSession()->pageTextContains('Your updated email address needs to be validated. Further instructions have been sent to your new email address.');
 
     $user_mail = $this->config('user.mail');
 
@@ -70,12 +79,12 @@ public function testMailChange() {
 
     // Check that the email has been successfully updated.
     $this->drupalGet($sent_mail_change_url);
-    $this->assertSession()->responseContains(t('Your email address has been changed to %mail.', ['%mail' => $new_mail]));
+    $this->assertSession()->responseContains(new FormattableMarkup('Your email address has been changed to %mail.', ['%mail' => $new_mail]));
 
     // Check that the change mail URL is not cached and expires after first use.
     $this->drupalGet($sent_mail_change_url);
     $this->assertNull($this->drupalGetHeader('X-Drupal-Cache'));
-    $this->assertSession()->responseContains(t('You have tried to use an email address change link that has either been used or is no longer valid. Please visit your account and change your email again.'));
+    $this->assertSession()->responseContains('You have tried to use an email address change link that has either been used or is no longer valid. Please visit your account and change your email again.');
 
     // Check that the user mail has been changed.
     self::assertSame(User::load($this->account->id())->getEmail(), $new_mail);
@@ -97,10 +106,10 @@ public function testMailChangeNoVerification() {
       'mail' => $new_mail,
       'current_pass' => $this->account->pass_raw,
     ];
-    $this->drupalPostForm($this->account->toUrl('edit-form'), $edit, t('Save'));
+    $this->drupalPostForm($this->account->toUrl('edit-form'), $edit, 'Save');
 
     // Check that the validation status message has not been displayed.
-    $this->assertSession()->pageTextNotContains(t('Your new email address needs to be validated. Further instructions have been sent to your new email address.'));
+    $this->assertSession()->pageTextNotContains('Your updated email address needs to be validated. Further instructions have been sent to your new email address.');
 
     // Check that no E-mail was sent to the old or to the new address.
     $this->assertEmpty($this->getMails());
@@ -113,7 +122,7 @@ public function testMailChangeNoVerification() {
    * Tests change of email for blocked users.
    */
   public function testBlockedUser() {
-    $timestamp = REQUEST_TIME - 1;
+    $timestamp = $this->time->getRequestTime() - 1;
     $account_cloned = clone $this->account;
     $account_cloned->block()->save();
     $this->drupalGet(MailChangeController::getUrl($account_cloned, [], $timestamp)->getInternalPath());
@@ -124,16 +133,16 @@ public function testBlockedUser() {
    * Tests change of email for expired timestamp.
    */
   public function testExpiredTimestamp() {
-    $timestamp = REQUEST_TIME - (24 * 60 * 60 + 1);
+    $timestamp = $this->time->getRequestTime() - (24 * 60 * 60 + 1);
     $this->drupalGet(MailChangeController::getUrl($this->account, [], $timestamp)->getInternalPath());
-    $this->assertSession()->responseContains(t('You have tried to use an email address change link that has expired. Please visit your account and change your email again.'));
+    $this->assertSession()->responseContains('You have tried to use an email address change link that has expired. Please visit your account and change your email again.');
   }
 
   /**
    * Tests change of email when other user is logged in.
    */
   public function testOtherUserLoggedIn() {
-    $timestamp = REQUEST_TIME - 1;
+    $timestamp = $this->time->getRequestTime() - 1;
     // Create other account and login with it.
     $current_account = $this->drupalCreateUser();
     $this->drupalLogin($current_account);
@@ -143,33 +152,33 @@ public function testOtherUserLoggedIn() {
     $this->account->setEmail($new_mail);
     $path = MailChangeController::getUrl($this->account, [], $timestamp)->getInternalPath();
     $this->drupalGet($path);
-    $this->assertSession()->responseContains(t('You are currently logged in as %user, and are attempting to confirm an email address change for another account. Please <a href=":logout">log out</a> and try using the link again.', ['%user' => $current_account->getAccountName(), ':logout' => Url::fromRoute('user.logout')->toString()]));
+    $this->assertSession()->responseContains(new FormattableMarkup('You are currently logged in as %user, and are attempting to confirm an email address change for another account. Please <a href=":logout">log out</a> and try using the link again.', ['%user' => $current_account->getAccountName(), ':logout' => Url::fromRoute('user.logout')->toString()]));
 
     // Retry as anonymous.
     $this->drupalLogout();
     $this->drupalGet($path);
-    $this->assertSession()->responseContains(t('Your email address has been changed to %mail.', ['%mail' => $new_mail]));
+    $this->assertSession()->responseContains(new FormattableMarkup('Your email address has been changed to %mail.', ['%mail' => $new_mail]));
   }
 
   /**
    * Tests change of email for timestamp in the future.
    */
   public function testFutureTimestamp() {
-    $timestamp = REQUEST_TIME + 60 * 60;
+    $timestamp = $this->time->getRequestTime() + 60 * 60;
     $this->drupalGet(MailChangeController::getUrl($this->account, [], $timestamp)->getInternalPath());
-    $this->assertSession()->responseContains(t('You have tried to use an email address change link that has either been used or is no longer valid. Please visit your account and change your email again.'));
+    $this->assertSession()->responseContains('You have tried to use an email address change link that has either been used or is no longer valid. Please visit your account and change your email again.');
   }
 
   /**
    * Tests change of email with the wrong hash.
    */
   public function testWrongHash() {
-    $timestamp = REQUEST_TIME - 1;
+    $timestamp = $this->time->getRequestTime() - 1;
     // Generate the hash for other user.
     $other_account = $this->drupalCreateUser();
     $hash = user_pass_rehash($other_account, $timestamp);
     $this->drupalGet(MailChangeController::getUrl($this->account, [], $timestamp, $hash)->getInternalPath());
-    $this->assertSession()->responseContains(t('You have tried to use an email address change link that has either been used or is no longer valid. Please visit your account and change your email again.'));
+    $this->assertSession()->responseContains('You have tried to use an email address change link that has either been used or is no longer valid. Please visit your account and change your email again.');
   }
 
   /**
diff --git a/core/modules/user/user.post_update.php b/core/modules/user/user.post_update.php
index c463cc7..7d41a35 100644
--- a/core/modules/user/user.post_update.php
+++ b/core/modules/user/user.post_update.php
@@ -21,13 +21,20 @@ function user_post_update_mail_change() {
   $config_factory->getEditable('user.settings')
     ->set('notify.mail_change_notification', FALSE)
     ->set('notify.mail_change_verification', FALSE)
-    ->set('mail_change_timeout', 86400)
     ->save();
 
-  $config = Yaml::parse(file_get_contents(__DIR__ . '/config/install/user.mail.yml'));
+  $mail_change_notification = [
+    'body' => "[user:display-name],\n\nA request to change your email address has been made at [site:name]. In order to complete the change you will need to follow the instructions sent to your new email address within one day.",
+    'subject' => 'Email change information for [user:display-name] at [site:name]',
+  ];
+  $mail_change_verification = [
+    'body' => "[user:display-name],\n\nA request to change your email address has been made at [site:name]. You need to verify the change by clicking on the link below or copying and pasting it in your browser:\n\n[user:mail-change-url]\n\nThis is a one-time URL, so it can be used only once. It expires after one day. If not used, your email address at [site:name] will not change.",
+    'subject' => 'Email change information for [user:display-name] at [site:name]',
+  ];
+
   $config_factory->getEditable('user.mail')
-    ->set('mail_change_notification', $config['mail_change_notification'])
-    ->set('mail_change_verification', $config['mail_change_verification'])
+    ->set('mail_change_notification', $mail_change_notification)
+    ->set('mail_change_verification', $mail_change_verification)
     ->save();
 }