Connecting to public IP on port 25

[terryrey]

Hi,

First off, let me explain that I am very new to VMware having just moved my small Windows web server from a physical server to a VM.  Please be kind if I am missing the obvious.

I have a Windows 2019 server running Plesk (control panel) and Smartermail.  I've been allocated 5 public IP's and am using one for web traffic and another for email.  My question is regarding email which although it works in so far as it can send and receive. 

The problem is, approximately 15% of outbound mail is being rejected (bounced) because the published IP address is public and the header shows the connecting (sending) address as that of the internal server IP.

I've tried adding the public IP as the outbound IP in the email config but not being on the VM it fails with a socket connection error and falls back to the internal IP. The failure is caused by the fact the mail software can't see the public mail IP to connect to port 25.

My question is, is it possible to achieve this and if so how do I do it?  If not, can you tell me how other VM's that send email overcome the public/private IP issue?

Thanks

Terry

[sjesse]

Sounds like your current server is behind a switch that is using network address translation, you would need to move your server to a network that has public ips. This has nothing to do with vmware, outside of making sure the network are available. Usually there are a pair of network adapters connected with vlans available that you tag on the vmware switches, and then you connect your vm to the portgroup with the vlan tag. You need to find out more about the external network configuration to be able to solve this.