I get the following error when I tried a test email to an address:
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
jqh1@josiah.net
Unrouteable address
Note jqh1@josiah.net is not my address, just an address in the chain.