about heirloom mailx

[Harry Putnam <reader@newsguy.com>]

Running jessie

Trying to use heirloom mailx to test various exim4 settings and It
works, but there is something in it that bugs me.  Makes me think I'm
doing something wrong.

Here is a typical example

  mailx -v recip@location.com
  Subject: what ever
  ble
  bleh
  .
  <ENTER>

And away it goes and outputs the smtp conversation ending in the
message

  [...]
  
  LOG: MAIN
  Completed

But then I never get the prompt back.

The cmdline is live... that is, if I type a cmd it will be executed
and then I get the prompt back.

Or I can hit Enter, or ^c to get the prompt back.

But shouldn't I get the prompt back when the process
completes.. without having to do anything extra?

Or am I just not using it correctly from the gate?