diff --git a/src/Bridges/MailDI/MailExtension.php b/src/Bridges/MailDI/MailExtension.php
index d53fbaa..f96067a 100644
--- a/src/Bridges/MailDI/MailExtension.php
+++ b/src/Bridges/MailDI/MailExtension.php
@@ -31,6 +31,16 @@ public function getConfigSchema(): Nette\Schema\Schema
 			'context' => Expect::arrayOf('array')->dynamic(),
 			'clientHost' => Expect::string()->dynamic(),
 			'persistent' => Expect::bool(false)->dynamic(),
+			'dkim' => Expect::anyOf(
+				Expect::null(),
+				Expect::structure([
+					'domain' => Expect::string()->dynamic(),
+					'selector' => Expect::string()->dynamic(),
+					'privateKey' => Expect::string()->dynamic()->required(),
+					'passPhrase' => Expect::string()->dynamic(),
+					'testMode' => Expect::bool(false)->dynamic(),
+				])->castTo('array')
+			),
 		])->castTo('array');
 	}
 
@@ -42,6 +52,18 @@ public function loadConfiguration()
 		$mailer = $builder->addDefinition($this->prefix('mailer'))
 			->setType(Nette\Mail\Mailer::class);
 
+		if ($this->config['dkim']) {
+			$dkim = $this->config['dkim'];
+			$dkim['privateKey'] = file_get_contents($dkim['privateKey']);
+			unset($this->config['dkim']);
+
+			$signer = $builder->addDefinition($this->prefix('signer'))
+				->setType(Nette\Mail\Signer::class)
+				->setFactory(Nette\Mail\DkimSigner::class, [$dkim]);
+
+			$mailer->addSetup('setSigner', [$signer]);
+		}
+
 		if ($this->config['smtp']) {
 			$mailer->setFactory(Nette\Mail\SmtpMailer::class, [$this->config]);
 		} else {
diff --git a/tests/Mail.DI/Mail.extension.phpt b/tests/Mail.DI/Mail.extension.phpt
index 7824db4..19cfbd2 100644
--- a/tests/Mail.DI/Mail.extension.phpt
+++ b/tests/Mail.DI/Mail.extension.phpt
@@ -23,6 +23,7 @@ test:
 	smtp: false
 ');
 Assert::type(Nette\Mail\SendmailMailer::class, $container1->getService('test.mailer'));
+Assert::false($container1->hasService('test.signer'));
 Assert::false($container1->hasService('nette.mailer'));
 
 
@@ -34,3 +35,16 @@ mail:
 ');
 Assert::type(Nette\Mail\SmtpMailer::class, $container2->getService('mail.mailer'));
 Assert::type($container2->getService('mail.mailer'), $container2->getService('nette.mailer'));
+Assert::false($container2->hasService('mail.signer'));
+
+
+$compiler = new DI\Compiler;
+$compiler->addExtension('mail', new MailExtension);
+$container3 = createContainer($compiler, '
+mail:
+	smtp: true
+	dkim:
+		privateKey: fixtures/private.key
+
+');
+Assert::type(Nette\Mail\DkimSigner::class, $container3->getService('mail.signer'));
diff --git a/tests/Mail.DI/fixtures/private.key b/tests/Mail.DI/fixtures/private.key
new file mode 100644
index 0000000..219d729
--- /dev/null
+++ b/tests/Mail.DI/fixtures/private.key
@@ -0,0 +1,15 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----