Trying to mail sent from Xojo Cloud

This code works from my desktop in debug build, but doesn’t work when deployed to Xojo Cloud. I am not an expert here, so I am hoping there is something obvious I need to do to get this to work. Any ideas?

// ss is an SMTPSecureSocket
  ss.address = "mydomain" // my email domain
  ss.ConnectionType = SSLSocket.TLSv12
  ss.port = 587
  ss.username = "support@mydomain"
  ss.password = "mypassword"
  
  Dim Mail As New EmailMessage
  mail.fromAddress="support@mydomain"
  mail.subject="test message"
  mail.bodyPlainText = "this is the body of the test message."
  
  mail.addRecipient "recipient_email_address"
  ss.messages.append mail
  ss.SendMail

You need to open the firewall port.

Yay - that worked!