Swift Error about recaptchacontact HOT 1 OPEN

grav.CRITICAL: Expected response code 220 but got code "", with message "" - Trace: 
#0 /usr/html/user/plugins/email/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php(289): Swift_Transport_AbstractSmtpTransport->_assertResponseCode('', Array) 
#1 /usr/html/user/plugins/email/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php(117): Swift_Transport_AbstractSmtpTransport->_readGreeting() 
#2 /usr/html/user/plugins/email/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/SendmailTransport.php(51): Swift_Transport_AbstractSmtpTransport->start() 
#3 /usr/html/user/plugins/email/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Mailer.php(79): Swift_Transport_SendmailTransport->start() 
#4 /usr/html/user/plugins/email/classes/Email.php(104): Swift_Mailer->send(Object(Swift_Message)) 
#5 /usr/html/user/plugins/recaptchacontact/recaptchacontact.php(280): Grav\Plugin\Email\Email->send(Object(Swift_Message)) 
#6 /usr/html/user/plugins/recaptchacontact/recaptchacontact.php(164): Grav\Plugin\ReCaptchaContactPlugin->sendEmail() 
#7 /usr/html/user/plugins/recaptchacontact/recaptchacontact.php(138): Grav\Plugin\ReCaptchaContactPlugin->processFormAction(Object(Grav\Common\Uri)) 
#8 /usr/html/user/plugins/recaptchacontact/recaptchacontact.php(90): Grav\Plugin\ReCaptchaContactPlugin->setupRecaptchaContact(Object(Grav\Common\Page\Page), true) 
#9 /usr/html/vendor/symfony/event-dispatcher/EventDispatcher.php(212): Grav\Plugin\ReCaptchaContactPlugin->onPageInitialized(Object(RocketTheme\Toolbox\Event\Event), 'onPageInitializ...', Object(RocketTheme\Toolbox\Event\EventDispatcher)) 
#10 /usr/html/vendor/symfony/event-dispatcher/EventDispatcher.php(44): Symfony\Component\EventDispatcher\EventDispatcher->doDispatch(Array, 'onPageInitializ...', Object(RocketTheme\Toolbox\Event\Event)) 
#11 /usr/html/vendor/rockettheme/toolbox/Event/src/EventDispatcher.php(23): Symfony\Component\EventDispatcher\EventDispatcher->dispatch('onPageInitializ...', Object(RocketTheme\Toolbox\Event\Event)) 
#12 /usr/html/system/src/Grav/Common/Grav.php(279): RocketTheme\Toolbox\Event\EventDispatcher->dispatch('onPageInitializ...', Object(RocketTheme\Toolbox\Event\Event)) 
#13 /usr/html/system/src/Grav/Common/Processors/PagesProcessor.php(26): Grav\Common\Grav->fireEvent('onPageInitializ...', Object(RocketTheme\Toolbox\Event\Event)) 
#14 /usr/html/system/src/Grav/Common/Grav.php(131): Grav\Common\Processors\PagesProcessor->process() 
#15 /usr/html/system/src/Grav/Common/Grav.php(370): Grav\Common\Grav->Grav\Common\{closure}() 
#16 [internal function]: Grav\Common\Grav::Grav\Common\{closure}('pages', 'Pages', Object(Closure)) 
#17 /usr/html/system/src/Grav/Common/Grav.php(346): call_user_func_array(Object(Closure), Array) 
#18 /usr/html/system/src/Grav/Common/Grav.php(132): Grav\Common\Grav->__call('measureTime', Array) 
#19 /usr/html/index.php(54): Grav\Common\Grav->process() 
#20 {main} [] []