Has anyone had luck sending dbmail via relay to an external server on an Azure VM (which appears to block SMTP outbound regardless of rules)?
Please read: Enhanced Azure Security for sending Emails – November 2017 Update which outlines the recommendations, options and restrictions for sending emails in Azure. 

In particular:


  For Pay-As-You-Go or Microsoft Partner Network subscriptions created
  after November 15, 2017, there will be technical restrictions blocking
  e-mail sent directly from VMs in these subscriptions.  Customers that
  need the ability to send e-mail from Azure VMs directly to external
  e-mail providers (not using an authenticated SMTP relay) can make a
  request to remove the restriction.  Requests will be reviewed and
  approved at Microsoft’s discretion and will be only granted after
  additional anti-fraud checks are performed.  To make a request, open a
  support case with the issue type Technical --> Virtual Network -->
  Connectivity --> Cannot send e-mail (SMTP/Port 25).  Be sure to add
  details about why your deployment needs to send mail directly to mail
  providers instead of going through an authenticated relay.