Ah yes, I like that misinformative message on those machines. The error has nothing to do with the recipient email address but everything to do with your machines ability to log into the outgoing email server (SMTP).
First off - in your TCP/IP settings
- make sure you have a domain name specified. If you aren't part of a domain I would use domain.local
- make sure your DNS address is correct
Second make sure your email settings are correct
-Is your smtp sever address correct?
-Does your email server need authenication (user/password)?
-Does your email server use encryption (SSL starttls)?
-What port is email server using/listening on?
for example to send using gmail
you must login using a fully qualified gmail email & password ex: XeroxWCscanner@gmail.com