reverted:
--- b/src/Tests/ContactTest.php
+++ a/src/Tests/ContactTest.php
@@ -3,7 +3,6 @@
 namespace Drupal\reroute_email\Tests;
 
 use Drupal\reroute_email\RerouteEmailTestBase;
-use Drupal\Core\StringTranslation\StringTranslationTrait;
 
 /**
  * Test Reroute Email module's ability to reroute mail sent from the Contact module form.
@@ -54,7 +53,7 @@
     $this->configureRerouteEmail();
 
     // Configure the contact settings to send to $original_destination.
+    $this->drupalPostForm('admin/structure/contact/manage/feedback', array('recipients' => $this->originalDestination), t('Save'));
-    $this->drupalPostForm('admin/structure/contact/manage/feedback', array('recipients' => $this->originalDestination), $this->t('Save'));
 
     // Go to the contact page and send an email.
     $post = array('subject[0][value]' => "Test test test", 'message[0][value]' => 'This is a test');
@@ -65,7 +64,7 @@
     $mails = $this->drupalGetMails();
 
     $mail = end($mails);
+    $this->assertMail('to', $this->rerouteDestination, t("Email was rerouted to @address", array('@address' => $this->rerouteDestination)));
-    $this->assertMail('to', $this->rerouteDestination, $this->t("Email was rerouted to @address", array('@address' => $this->rerouteDestination)));
 
     // Check if original destination email address is in rerouted email body.
     $this->assertOriginallyTo($mail['body'], 'Found the correct "Originally to" line in the body');
@@ -77,11 +76,11 @@
     $this->configureRerouteEmail("{$this->rerouteDestination}, $additional_destination");
 
     // Configure the contact settings to point to the additional recipient.
+    $this->drupalPostForm('admin/structure/contact/manage/feedback', array('recipients' => $additional_destination), t('Save'));
-    $this->drupalPostForm('admin/structure/contact/manage/feedback', array('recipients' => $additional_destination), $this->t('Save'));
 
     // Go to the contact page and send an email.
     $post = array('subject[0][value]' => "Test test test", 'message[0][value]' => 'This is a test');
+    $this->drupalPostForm("contact", $post, t("Send message"));
-    $this->drupalPostForm("contact", $post, $this->t("Send message"));
     $this->assertText($this->confirmation_message);
     $this->assertMail('to', $additional_destination, 'Email was not rerouted because destination was in whitelist');
 
@@ -90,23 +89,23 @@
     $this->configureRerouteEmail(NULL, FALSE);
 
     // Set the contact form to send to original_destination.
+    $this->drupalPostForm('admin/structure/contact/manage/feedback', array('recipients' => $this->originalDestination), t('Save'));
-    $this->drupalPostForm('admin/structure/contact/manage/feedback', array('recipients' => $this->originalDestination), $this->t('Save'));
     // Go to the contact page and send an email.
     $post = array('subject[0][value]' => "Test test test", 'message[0][value]' => 'This is a test');
+    $this->drupalPostForm("contact", $post, t("Send message"));
-    $this->drupalPostForm("contact", $post, $this->t("Send message"));
     $this->assertText($this->confirmation_message);
     $mails = $this->drupalGetMails();
     $mail = end($mails);
     // Mail should not be rerouted - should go to $original_destination.
     $this->assertMail('to', $this->originalDestination, 'Mail not rerouted - sent to original destination.');
+    $this->verbose(t("Email 'to' was: <pre>@mail_to</pre>", array('@mail_to' => $mail['to'])));
-    $this->verbose($this->t("Email 'to' was: <pre>@mail_to</pre>", array('@mail_to' => $mail['to'])));
 
     // Configure to reroute without body injection.
     $this->configureRerouteEmail(NULL, TRUE, FALSE);
 
     // Go to the contact page and send an email.
     $post = array('subject[0][value]' => "Test test test", 'message[0][value]' => 'This is a test');
+    $this->drupalPostForm("contact", $post, t("Send message"));
-    $this->drupalPostForm("contact", $post, $this->t("Send message"));
     $this->assertText($this->confirmation_message);
     $mails = $this->drupalGetMails();
     $mail = end($mails);
reverted:
--- b/src/Tests/TestEmailTest.php
+++ a/src/Tests/TestEmailTest.php
@@ -3,7 +3,6 @@
 namespace Drupal\reroute_email\Tests;
 
 use Drupal\reroute_email\RerouteEmailTestBase;
-use Drupal\Core\StringTranslation\StringTranslationTrait;
 
 /**
  * Test Reroute Email's form for sending a test email.
@@ -26,7 +25,7 @@
 
     // Check Subject field default value.
     $this->drupalGet("admin/config/development/reroute_email/test");
+    $this->assertFieldByName('subject', t("Reroute Email Test"), 'The expected default value was found for the Subject field.');
-    $this->assertFieldByName('subject', $this->t("Reroute Email Test"), 'The expected default value was found for the Subject field.');
 
     // Submit the Test Email form to send an email to be rerouted.
     $post = array(
@@ -36,8 +35,8 @@
       'subject' => "Test Reroute Email Test Email Form",
       'body' => 'Testing email rerouting and the Test Email form',
     );
+    $this->drupalPostForm("admin/config/development/reroute_email/test", $post, t("Send email"));
+    $this->assertText(t("Test email submitted for delivery from test form."));
-    $this->drupalPostForm("admin/config/development/reroute_email/test", $post, $this->t("Send email"));
-    $this->assertText($this->t("Test email submitted for delivery from test form."));
     $mails = $this->drupalGetMails();
     $mail = end($mails);
     // Check rerouted email to.
@@ -54,8 +53,8 @@
     $this->assertFalse(strpos($mail['body'], $post['body']) === FALSE, 'Body contains the value submitted through the form');
 
     // Check required To field.
+    $this->drupalPostForm("admin/config/development/reroute_email/test", array('to' => ''), t("Send email"));
+    $this->assertText(t("To field is required."));
-    $this->drupalPostForm("admin/config/development/reroute_email/test", array('to' => ''), $this->t("Send email"));
-    $this->assertText($this->t("To field is required."));
 
     // Test form submission with email rerouting and invalid email addresses.
     $post = array(
@@ -63,9 +62,9 @@
       'cc' => "Cc address invalid format",
       'bcc' => "Bcc address invalid format",
     );
+    $this->drupalPostForm("admin/config/development/reroute_email/test", $post, t("Send email"));
-    $this->drupalPostForm("admin/config/development/reroute_email/test", $post, $this->t("Send email"));
     // Successful submission with email rerouting enabled.
+    $this->assertText(t("Test email submitted for delivery from test form."));
-    $this->assertText($this->t("Test email submitted for delivery from test form."));
     $mails = $this->drupalGetMails();
     $mail = end($mails);
     // Check rerouted email to.
@@ -83,13 +82,13 @@
     $this->configureRerouteEmail(NULL, FALSE);
 
     // Submit the test email form again with previously used invalid addresses.
+    $this->drupalPostForm("admin/config/development/reroute_email/test", $post, t("Send email"));
-    $this->drupalPostForm("admin/config/development/reroute_email/test", $post, $this->t("Send email"));
     // Check invalid email addresses are still passed to the mail system.
     $mails = $this->drupalGetMails();
     $mail = end($mails);
     // Check rerouted email to.
     $this->assertMail('to', $post['to'], format_string('To email address is correctly set to submitted value: @address.', array('@address' => $post['to'])));
+    $this->verbose(t('Sent email values: <pre>@mail</pre>', array('@mail' => var_export($mail, TRUE))));
-    $this->verbose($this->t('Sent email values: <pre>@mail</pre>', array('@mail' => var_export($mail, TRUE))));
     // Check the Cc and Bcc headers are the ones submitted through the form.
     $this->assertTrue($mail['headers']['Cc'] == $post['cc'], format_string('Cc is correctly set to submitted value: @address', array('@address' => $post['cc'])));
     $this->assertTrue($mail['headers']['Bcc'] == $post['bcc'], format_string('Bcc is correctly set to submitted value: @address', array('@address' => $post['bcc'])));
reverted:
--- b/src/Tests/UnusualMessageFieldsTest.php
+++ a/src/Tests/UnusualMessageFieldsTest.php
@@ -2,7 +2,6 @@
 namespace Drupal\reroute_email\Tests;
 
 use Drupal\reroute_email\RerouteEmailTestBase;
-use Drupal\Core\StringTranslation\StringTranslationTrait;
 
 /**
  * Test handling of
@@ -59,7 +58,7 @@
     \Drupal::getContainer()
       ->get('plugin.manager.mail')
       ->mail('reroute_email_test', 'test_reroute_email', $test_message['to'], $langcode, $test_message['params']);
+    $this->verbose(t('Test email message values: <pre>@test_message</pre>', array('@test_message' => var_export($test_message, TRUE))));
-    $this->verbose($this->t('Test email message values: <pre>@test_message</pre>', array('@test_message' => var_export($test_message, TRUE))));
 
     $mails = $this->drupalGetMails();
     $mail = end($mails);
@@ -74,7 +73,7 @@
 
     // Check the watchdog entry logged by reroute_email_test_mail_alter.
     $this->drupalGet('admin/reports/dblog');
+    $this->assertRaw(t('A String was detected in the body'), 'Recorded in recent log messages: a String was detected in the body.');
-    $this->assertRaw($this->t('A String was detected in the body'), 'Recorded in recent log messages: a String was detected in the body.');
 
     // Test the robustness of the CC and BCC keys in headers.
     $this->assertTrue($mail['headers']['X-Rerouted-Original-Cc'] == $test_message['params']['headers'][$test_cc_key], format_string('X-Rerouted-Original-Cc is correctly set to @test_cc_address, although Cc header message key provided was: @test_cc_key', array(