Mail Delivery System, Mail delivery failed:

Delete it and forget about it.

It's likely a fake bounce message being used by scammers to get you to verify your email address to them. If you were able to check the content you'd probably see that the email they're complaining about did not originate from IP related to HughesNet's email servers.

The alternative explanation is that you have malware that is acting as a spambot, but that's not as likely. Those usually forge the From: email address to be something other than your actual address so the bounce message would have gone somewhere else.