The readme.txt file says:

—
To run this example, you should create EAP server runtime
with the name is "jboss-soa-p.5.0 Runtime" in your workspace.

You will need to place a copy of camel-mail-2.4.0.jar into esbcontent/lib.

You will need to copy mail-ra.jar from
${jboss.server.home.dir}/deploy/mail-ra.rar.
—

Two problems:

1) camel-mail-2.4.0.jar is already installed in esbcontent/lib

2) Where should the user copy mail-ra.jar?