This process seems like it would be fairly straight forward, but I cannot get it to work. I am using a Peplink Balance 380 firmware version 5.4.7 build 2423.
What I am trying to accomplish is:
Block outbound traffic on SMTP Port 25 only for ALL Internal devices.
Then, allow SMTP Outbound traffic on Port 25 for one single internal IP only.
The reason, simple. Sometimes PCs get viruses that send outgoing emails. We need to prevent any emailing viruses from sending unauthroized spam on our network so our IP does not become blacklisted.
I can get block all traffic on Port 25 to work just fine. I cannot however, get my email server successfully communicating outbound emails while the network is blocked.
Thanks for any assistance provided,