I want our exchange 5.5 server to be able to relay messages from external users, most of whom are in international locations. For various reasons, they are unable to use a local SMTP servers, so they need to use our Server as both the incoming and outgoing mail server.
This means opening ports 25 and 110 in our firewall for SMTP and POP3 transfers, right?
Is this a safe and reliable way to run exchange?
Anything I should do to make this run better/safer/more reliably? Thanks.
