I need to allow an external(cloud) app to send e-mail via on-premisse exchange server.
So,I need to configure open relay for two public IP addresses.
I checked those two IP address and they are Microsoft IP addresses.So,I presume it is Azure app.
Is it OK to allow open relay to public IPs like Microsoft?
If it is OK,I only need to add those two IPs on receive connector(anonymous) ?