I run my own mail server on Azure for my domain. After deploying a new VM that will replace my existing server I stumbled upon the inability to run trivial email diagnostic tests like port25's DKIM tester. I found this Microsoft article showing that MS decided to shut down the ability for new deployments to run port 25 and that a support request should be made to unlock port 25 outbound.
The article says that the support request must be for a technical issue, however my subscription does not allow technical support requests unless I buy a paid MSDN subscription.
I run my own domain on a very low budget and mostly for fun than for profit, but I am trying to reduce the number of servers after shutting down my ecommerce hosting business. So I wouldn't like to pay for a subscription that is worth more than the two servers I currently run.
How can I request port 25 unlock and go through Microsoft's screening without the ability to issue technical requests?
The answer is in the article you linked: use an authenticated and encrypted mail submission agent.
However, this will limit your ability to connect to MTAs on port 25. Presumably, this is by design, as there are less attentive Azure customers contributing to the junk mail problem.