When sendmail scans the network hardware to find
other names for the local host, it uses only those names that are
new. Each new name was printed by the -d0.4
debugging switch described earlier. To see every name that
sendmail finds, new and old alike, use the
-d0.20 debugging switch:
128.32.201.55
already found
127.0.0.1
found new
a.k.a.: [127.0.0.1]