Is UTM mail proxy still relevant?

Question

My question is based around the fact that most mail systems use either 465 or 587 for outgoing mail? The proxy only listens on port 25. 
 The pop proxy is no better it listens on 110 where as most systems use 143, 993. 
 So to those in the know are there any plans to upgrade the proxy so that it will work with other mail protocols? 
 Ian

DouglasFoster · Answer

Some UTM functions are to protect the desktop clients on your network from hostile servers on the internet, while others are intended to protect the servers on your network from hostile devices on the internet. 
 It appears that you are thinking of the SMTP proxy as a device to protect the connection between Outlook on your PC from your mail server. The POP3 proxy plays that role, you can think of it as a second line of defense in case your mail server is successfully attacked. However, the SMTP proxy is intended to protect a mail server from incoming messages sent by a hostile server on the internet. 
 You are right that your mail program uses ports 25, 465, or 587 to send messages to the mail server. That traffic is trusted because you have to log in to send messages (or you need a special exemption based on your IP). 
 Mail servers also transmit to other servers using port 25 as the target. The remote server does not authenticate and is not trusted, but it is allowed to send messages to the accounts on the mail server. The UTM SMTP proxy intercepts that traffic to reduce the risk that a hostile message will be accepted. 
 If your mail does not flow into your UTM before flowing into your mail server, then the SMTP proxy is not intended for your situation. 
 Hope this helps.