diff --git a/sources/Core/Email/Transport/SymfonyPHPMailTransport.php b/sources/Core/Email/Transport/SymfonyPHPMailTransport.php
index 7f2334ff25..7881ba4299 100644
--- a/sources/Core/Email/Transport/SymfonyPHPMailTransport.php
+++ b/sources/Core/Email/Transport/SymfonyPHPMailTransport.php
@@ -20,7 +20,7 @@ class SymfonyPHPMailTransport extends AbstractTransport
 	{
 		$oHeaders = $oRawEmail->getHeaders();
 
-		return $oHeaders->get('To')->getBodyAsString();
+		return $oHeaders->get('To') ? $oHeaders->get('To')->getBodyAsString() : '';
 	}
 
 	/**
diff --git a/tests/php-unit-tests/unitary-tests/sources/core/Email/Transport/SymfonyPHPMailTransportTest.php b/tests/php-unit-tests/unitary-tests/sources/core/Email/Transport/SymfonyPHPMailTransportTest.php
new file mode 100644
index 0000000000..97f1db109d
--- /dev/null
+++ b/tests/php-unit-tests/unitary-tests/sources/core/Email/Transport/SymfonyPHPMailTransportTest.php
@@ -0,0 +1,22 @@
+<?php
+
+use Combodo\iTop\Core\Email\Transport\SymfonyPHPMailTransport;
+use Combodo\iTop\Test\UnitTest\ItopTestCase;
+use Symfony\Component\Mime\Email;
+
+class SymfonyPHPMailTransportTest extends ItopTestCase
+{
+	public function testPrepareMustNotThrowErrorWhenToHeaderIsMissing(): void
+	{
+		$oEmail = new Email()
+			->from('sender@example.com')
+			->cc('cc1@example.com', 'cc2@example.com')
+			->text('Body');
+
+		$oTransport = new SymfonyPHPMailTransport();
+
+		$oTransport->prepareTo($oEmail);
+		$this->assertTrue(true); // if no error is thrown, the test passes
+
+	}
+}