I am preparing a single-server Zimbra config running on a dual-homed firewall. To get things working, I had to open port 7025 (LMTP?) on my external interface. According to nmap, LMTP is ONLY bound to my external interface. Is this necessary, or even recommended?
Isn't LMTP only used for routing mail from the MTA to the user's mailboxes? On a single-server config, I would think that it would be most secure as well as most efficient to bind LMTP to localhost, or at the very least, my internal interface.
If localhost is preferable, how/where do I make the change?
Thanks in advance for your assistance.