Cannot reproduce Register with provider not check email for valid

[WeaponOwl]

Affected version

2.0.6

Received next server error today. User have it register with facebook.

Swift_TransportException: Email to 021@985920427 failed: Expected response code 250 but got code "554", with message "554 Transaction failed: Invalid domain name: '985920427'. " src/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php:383

#0 src/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php(281): Swift_Transport_AbstractSmtpTransport->_assertResponseCode('554 Transaction...', Array)
#1 src/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/EsmtpTransport.php(270): Swift_Transport_AbstractSmtpTransport->executeCommand('\r\n.\r\n', Array, Array)
#2 src/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php(333): Swift_Transport_EsmtpTransport->executeCommand('\r\n.\r\n', Array)
#3 src/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php(428): Swift_Transport_AbstractSmtpTransport->_streamMessage(Object(Swift_Message))
#4 src/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php(444): Swift_Transport_AbstractSmtpTransport->_doMailTransaction(Object(Swift_Message), 'no-reply+89e5cb...', Array, Array)
#5 src/vendor/swiftmailer/swiftmailer/lib/classes/Swift/Transport/AbstractSmtpTransport.php(176): Swift_Transport_AbstractSmtpTransport->_sendTo(Object(Swift_Message), 'no-reply+89e5cb...', Array, Array)
#6 src/XF/Mail/Mailer.php(289): Swift_Transport_AbstractSmtpTransport->send(Object(Swift_Message), Array)
#7 src/XF/Mail/Queue.php(65): XF\Mail\Mailer->send(Object(Swift_Message))
#8 src/XF/Job/MailQueue.php(11): XF\Mail\Queue->run(7.9999978542328)
#9 src/XF/Job/Manager.php(241): XF\Job\MailQueue->run(7.9999978542328)
#10 src/XF/Job/Manager.php(187): XF\Job\Manager->runJobInternal(Array, 7.9999978542328)
#11 src/XF/Job/Manager.php(76): XF\Job\Manager->runJobEntry(Array, 7.9999978542328)
#12 job.php(15): XF\Job\Manager->runQueue(false, 8)
#13 {main}

As i know, there is email validation if user input it manually, but i not found validation on register using facebook/google/another provider.
Look like this user on register receive phone number (021-985920427) at email row...