When we set up a role in a public folder, with "reply with" the reply
will only be sent to the people ho has an internal e-mail address.
All external addresses will seem to work, but the e-mail does not go
out the external smtp.
If you take a cc in the mail to an internal e-mail address, you can
see that it's also trying to send the e-mail to the external address,
but it never goes out of the server.