A.If you can receive Internet mail, look at the Received: lines at the top of messages to discover the route followed. B. Look at RFC 822 to discover the exact range of header lines that can appear in...

messages to discover the route followed.

B.
Look at RFC 822 to discover the exact range of header lines that can appear

in Internet mail messages.

C.
If you can send Internet mail, experiment with source routing of messages

by using the extended form of destination identifier (details in RFC 822).