[Mailer] Fix SMTP Authentication when using STARTTLS

Author: DjLeChuck

Transport/Smtp/EsmtpTransport.php

@@ -115,6 +115,7 @@ protected function doHeloCommand(): void
 
             try {
                 $response = $this->executeCommand(sprintf("EHLO %s\r\n", $this->getLocalDomain()), [250]);
+                $capabilities = $this->getCapabilities($response);
             } catch (TransportExceptionInterface $e) {
                 parent::doHeloCommand();