The cause of the problem was that I had added the hostname to the 127.0.0.1 entry in /etc/hosts. I guess on reverse lookup of the hostname, /etc/hosts was used for some reason to reveal localhost.localdomain. A special thanks to Patrick Tudor who pointed me in this direction. The cause of the second problem , it turns out, was non-qmail related, but a DNS issue on the remote machine I was sending from. A special thanks to Greg Haverkamp for this one.
