According to mxlookup tool, it looks like everything is great. Still can't receive mail externally. It looks like it's timing out before being accepted by postifix. I don't know enough to begin to troubleshoot that problem.
As a reminder, I CAN telnet to port 25 from inside or outside, but CAN'T send "telnet mail" from outside the network, only inside it.
Thanks in advance for any help.