On Mon, 2006-11-13 at 09:55 -0500, Patrick Doyle wrote: > Anyway I have a Linux box parked on the inside of a firewall which, > for whatever reason, won't let the box connect to the company's mail > server via its MX record IP address. I can, however, connect to the > mail server using its internal IP address. (Verified by telnet > a.b.c.d 25). Is the MX record for an external address? Perhaps internal IPs can't connect to external IPs, due to firewalling rules. If so, the obvious answer would be to have split DNS, with the server respoding with internal IPs to internal queries, and external IPs to external queries. Disallowing an internal IP to connect to an external IP is a guard against spoofing attacks, where the attacker hopes that using a faked internal address will help them get past security. > Can anybody point me to where I can learn how to configure my Linux > box to use the internal IP address for my company's smtp server > instead of the external IP address? I think that if you wanted to specify an IP address in the sendmail configuration, you enclosed in square brackets, so it didn't try to resolve it. i.e. [192.168.1.2] Read the documentation about that, it is covered. > I tried the obvious fix of the internal IP address for mycompany.com > in /etc/hosts, but that didn't work The hosts file can't be used for MX queries. -- (Currently testing FC5, but still running FC4, if that's important.) Don't send private replies to my address, the mailbox is ignored. I read messages from the public lists.
