diff --git a/tests/Settings/Controller/MailSettingsControllerTest.php b/tests/Settings/Controller/MailSettingsControllerTest.php
index 79fe0683cc..ed241ed053 100644
--- a/tests/Settings/Controller/MailSettingsControllerTest.php
+++ b/tests/Settings/Controller/MailSettingsControllerTest.php
@@ -74,6 +74,7 @@ class MailSettingsControllerTest extends \Test\TestCase {
 					'mail_smtpauthtype' => 'NTLM',
 					'mail_smtpauth' => 1,
 					'mail_smtpport' => '25',
+					'mail_sendmailmode' => null,
 				]],
 				[[
 					'mail_domain' => 'nextcloud.com',
@@ -86,6 +87,7 @@ class MailSettingsControllerTest extends \Test\TestCase {
 					'mail_smtpport' => '25',
 					'mail_smtpname' => null,
 					'mail_smtppassword' => null,
+					'mail_sendmailmode' => null,
 				]]
 			);
 
@@ -98,7 +100,8 @@ class MailSettingsControllerTest extends \Test\TestCase {
 			'mx.nextcloud.org',
 			'NTLM',
 			1,
-			'25'
+			'25',
+			null
 		);
 		$this->assertSame(Http::STATUS_OK, $response->getStatus());
 
@@ -111,7 +114,8 @@ class MailSettingsControllerTest extends \Test\TestCase {
 			'mx.nextcloud.org',
 			'NTLM',
 			0,
-			'25'
+			'25',
+			null
 		);
 		$this->assertSame(Http::STATUS_OK, $response->getStatus());
 
diff --git a/tests/lib/Mail/MailerTest.php b/tests/lib/Mail/MailerTest.php
index ddae38ff54..4117498885 100644
--- a/tests/lib/Mail/MailerTest.php
+++ b/tests/lib/Mail/MailerTest.php
@@ -48,30 +48,54 @@ class MailerTest extends TestCase {
 		);
 	}
 
-	public function testGetSendMailInstanceSendMail() {
+	/**
+	 * @return array
+	 */
+	public function sendmailModeProvider(): array {
+		return [
+			'smtp' => ['smtp', ' -bs'],
+			'pipe' => ['pipe', ' -t'],
+		];
+	}
+
+	/**
+	 * @dataProvider sendmailModeProvider
+	 * @param $sendmailMode
+	 * @param $binaryParam
+	 */
+	public function testGetSendmailInstanceSendMail($sendmailMode, $binaryParam) {
 		$this->config
-			->expects($this->once())
+			->expects($this->exactly(2))
 			->method('getSystemValue')
-			->with('mail_smtpmode', 'smtp')
-			->will($this->returnValue('sendmail'));
+			->will($this->returnValueMap([
+				['mail_smtpmode', 'smtp', 'sendmail'],
+				['mail_sendmailmode', 'smtp', $sendmailMode],
+			]));
 
 		$path = \OC_Helper::findBinaryPath('sendmail');
 		if ($path === null) {
 			$path = '/usr/sbin/sendmail';
 		}
 
-		$expected = new \Swift_SendmailTransport($path . ' -bs');
+		$expected = new \Swift_SendmailTransport($path . $binaryParam);
 		$this->assertEquals($expected, self::invokePrivate($this->mailer, 'getSendMailInstance'));
 	}
 
-	public function testGetSendMailInstanceSendMailQmail() {
+	/**
+	 * @dataProvider sendmailModeProvider
+	 * @param $sendmailMode
+	 * @param $binaryParam
+	 */
+	public function testGetSendmailInstanceSendMailQmail($sendmailMode, $binaryParam) {
 		$this->config
-			->expects($this->once())
+			->expects($this->exactly(2))
 			->method('getSystemValue')
-			->with('mail_smtpmode', 'smtp')
-			->will($this->returnValue('qmail'));
+			->will($this->returnValueMap([
+				['mail_smtpmode', 'smtp', 'qmail'],
+				['mail_sendmailmode', 'smtp', $sendmailMode],
+			]));
 
-		$this->assertEquals(new \Swift_SendmailTransport('/var/qmail/bin/sendmail -bs'), self::invokePrivate($this->mailer, 'getSendMailInstance'));
+		$this->assertEquals(new \Swift_SendmailTransport('/var/qmail/bin/sendmail' . $binaryParam), self::invokePrivate($this->mailer, 'getSendMailInstance'));
 	}
 
 	public function testGetInstanceDefault() {
@@ -83,8 +107,10 @@ class MailerTest extends TestCase {
 	public function testGetInstanceSendmail() {
 		$this->config
 			->method('getSystemValue')
-			->with('mail_smtpmode', 'smtp')
-			->willReturn('sendmail');
+			->will($this->returnValueMap([
+				['mail_smtpmode', 'smtp', 'sendmail'],
+				['mail_sendmailmode', 'smtp', 'smtp'],
+			]));
 
 		$mailer = self::invokePrivate($this->mailer, 'getInstance');
 		$this->assertInstanceOf(\Swift_Mailer::class, $mailer);
diff --git a/tests/lib/Settings/Admin/MailTest.php b/tests/lib/Settings/Admin/MailTest.php
index 436a795322..1a1d090418 100644
--- a/tests/lib/Settings/Admin/MailTest.php
+++ b/tests/lib/Settings/Admin/MailTest.php
@@ -95,6 +95,11 @@ class MailTest extends TestCase {
 			->method('getSystemValue')
 			->with('mail_smtppassword', '')
 			->willReturn('mypassword');
+		$this->config
+			->expects($this->at(10))
+			->method('getSystemValue')
+			->with('mail_sendmailmode', 'smtp')
+			->willReturn('smtp');
 
 		$expected = new TemplateResponse(
 			'settings',
@@ -111,6 +116,7 @@ class MailTest extends TestCase {
 				'mail_smtpauth'         => true,
 				'mail_smtpname'         => 'smtp.sender.com',
 				'mail_smtppassword'     => '********',
+				'mail_sendmailmode'		=> 'smtp',
 			],
 			''
 		);