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I want to land emails from multiple internal systems on Exchange online.
Which is more secure, "internal systems >> smtp relay server(no load balancing) >> Exo" or "internal systems >> Exo"?
I prefer ""internal systems >> smtp relay server(no load balancing) >> Exo"
that way I only need to open port 25 outbound from the internal SMTP relay to ExO rather then open up it up for each internal system.
Thansk alot. And I'm sorry. Please tell me a little more detail.
Currently, we are considering abolishing the smtp relay server to reduce costs. Which configuration do hackers prefer to attack?
Open up it up for each internal system?
Is it because the firewall opens multiple connection ports?
IF you can open less outbound ports than its less management and more control. That to me is safer and makes the most sense.
If cost is really an issue way that with the cost of monitoring all the outbound ports and maintaining the list of allowed outbound IPs
Also, the cost of managing certificates on each on-prem system server to use the inbound connector on the 365 side.
True!!!!! Thank you very much.
I will consider based on your advice. Thanks alot!!!!!!!!!!