Recently, I was contacted by Mr. Joseph Corona who asked me more information about how I managed to get a medal of honor for my grandfather (more details here and here).

I answered him back, but my message was rejected by his email server:

Address not found
Your message wasn't delivered to ...@optonline.net because the address couldn't be found, or is unable to receive mail.

The response from the remote server was:
550 5.1.1 Invalid recipient ...@optonline.net

I wrote to postmaster@optonline.net to notify this problem, but the message bounced back as well. As I don’t know how to get in touch with Mr. Joseph Corona otherwise, I hope he will read this communication and write me again using a different email address. I would be glad to help him to get the medal for his father.