How can we restrict SMTP service to be used on localhost only?
Our websites are using localhost SMTP but we do not want any mail clients to use our server on SMTP port.
Our server is Windows Server 2008 R2 and using Mail Enabled Professional Edition V1.
Thanks.
Best Answer
My advice, especially for SMTP, is to protect yourself with as many layers of security as possible, especially if you have other people with admin access to the server, turning things like firewalls on and off... Here's how I'd do it:
Here's a guide on how to actually do steps 2 and 3. #2 above is shown in step 12 of the guide, and #3 above is shown in steps 13 and 15 of the guide.
Why have these 3 layers? Short answer: minimize risk of security incidents and other undesirable issues. Long answer:
I hope this helps! Good luck and take care!