I have recently aquired an NT4/Exchange server used for Email. The compnay would now like to set up access to their email from the internet. I have found a couple of ways to do this, but I have some questions about security, and would like some opinions.
1: If I set it up to use POP3/SMTP access from Outlook Express, I am concerned that someone could port scan my static IP and start using my SMTP to spam, since it doesnt appear to need authentication to access the SMTP side (only the POP3 is asking for a logon) Is this a valid concern, or is there a way to force authentication so that only my users could get mail into the server?
2: If I set it up to use Outlook over the internet, and open up port 135 on my firewall, am I running a risk of someone port scanning my IP and then getting into my Exchange server? Or is the NT authentication fairly tight?
Since the employees use the Exchange calendar and contacts, I would prefer to use the full Outlook client over the internet, but if the performance is lacking I am not opposed to useing POP3/SMTP… Any advice or experiences would be greatly appreciated.
