diff --git a/Message/Mail/Email.php b/Message/Mail/Email.php
index 2ed6e0306..c89221394 100644
--- a/Message/Mail/Email.php
+++ b/Message/Mail/Email.php
@@ -692,7 +692,7 @@ class Email implements MessageInterface
                 : $this->messageDate->format('D, j M Y H:i:s O'))
             . self::$LE;
 
-        if ($this->mailer === SubmitType::MAIL) {
+        if ($this->mailer !== SubmitType::MAIL) {
             $result .= \count($this->to) > 0
                 ? $this->addrAppend('To', $this->to)
                 : 'To: undisclosed-recipients:;' . self::$LE;
@@ -706,7 +706,9 @@ class Email implements MessageInterface
         }
 
         // sendmail and mail() extract Bcc from the header before sending
-        if (($this->mailer === SubmitType::MAIL || $this->mailer === SubmitType::SENDMAIL || $this->mailer === SubmitType::QMAIL)
+        if (($this->mailer === SubmitType::MAIL
+                || $this->mailer === SubmitType::SENDMAIL
+                || $this->mailer === SubmitType::QMAIL)
             && \count($this->bcc) > 0
         ) {
             $result .= $this->addrAppend('Bcc', $this->bcc);
diff --git a/Utils/ArrayUtils.php b/Utils/ArrayUtils.php
index 4fe49df1a..88095675c 100644
--- a/Utils/ArrayUtils.php
+++ b/Utils/ArrayUtils.php
@@ -437,7 +437,7 @@ final class ArrayUtils
         $diff = [];
         foreach ($values1 as $key => $value) {
             if (\is_array($value)) {
-                if (!array_key_exists($key, $values2) || !\is_array($values2[$key])) {
+                if (!\array_key_exists($key, $values2) || !\is_array($values2[$key])) {
                     $diff[$key] = $value;
                 } else {
                     $subDiff = self::array_diff_assoc_recursive($value, $values2[$key]);
diff --git a/tests/Message/Mail/MailHandlerTest.php b/tests/Message/Mail/MailHandlerTest.php
index d89dae788..47c56d350 100644
--- a/tests/Message/Mail/MailHandlerTest.php
+++ b/tests/Message/Mail/MailHandlerTest.php
@@ -42,6 +42,20 @@ class MailHandlerTest extends \PHPUnit\Framework\TestCase
         self::assertTrue($mailer->send($mail));
     }
 
+    public function testSendTextWithSendmail() : void
+    {
+        $mailer = new MailHandler();
+        $mailer->setMailer(SubmitType::SENDMAIL);
+
+        $mail = new Email();
+        $mail->setFrom('dennis.eichhorn@orange-management.org', 'Dennis Eichhorn');
+        $mail->addTo('info@orange-management.org', 'Dennis Eichhorn');
+        $mail->subject = 'Test email';
+        $mail->body    = 'This is some content';
+
+        self::assertTrue($mailer->send($mail));
+    }
+
     public function testReceiveMailWithImap() : void
     {/*
         $mailer = new Imap();
diff --git a/tests/System/File/Local/DirectoryTest.php b/tests/System/File/Local/DirectoryTest.php
index 9e670ced2..a10b17b0b 100644
--- a/tests/System/File/Local/DirectoryTest.php
+++ b/tests/System/File/Local/DirectoryTest.php
@@ -398,7 +398,7 @@ class DirectoryTest extends \PHPUnit\Framework\TestCase
     {
         $dirTestPath = __DIR__ . '/dirtest';
         self::assertCount(6, Directory::list($dirTestPath, '*', true));
-        self::assertEquals(['sub/test2.txt', 'sub/test4.md', 'sub/path/test3.txt'], Directory::list($dirTestPath, 'test[0-9]+.*', true));
+        self::assertEquals([], \array_diff(['sub/test2.txt', 'sub/test4.md', 'sub/path/test3.txt'], Directory::list($dirTestPath, 'test[0-9]+.*', true)));
 
         self::assertCount(2, Directory::list($dirTestPath, '*', false));
     }