I installed Mail In A Box on a friend’s VPS hosted by Microsoft Azure. It is an Ubuntu 22.04 LTS but port 53 is blocked, so DNS services cannot run. Also, the ports such as port 25, port 587, and port 465.
Has anyone used Microsoft Azure with Mail In A Box?
UPDATE: I noticed Microsoft Azure VPSes are not dual stack and do not support IPv6. My VPS has IPv4 address. Its a tragedy Microsoft does not approve of IPv6 and makes using IPv6 with Ubuntu very difficult.
UPDATE: I solved the problem 
as Azure allows to unblock ports in the Networking section.