Jonathan Sobel is already gone...

From:"MAILER-DAEMON@yahoo .com"

I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

<jsobel@corp.sourceforge.co m>:
208.48.95.23 does not like recipient.
Remote host said: 550 unknown user
Giving up on 208.48.95.23.



This is an automatically generated Delivery Status Notification

Delivery to the following recipient failed permanently:

jsobel@corp.sourceforge.com

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 unknown user (state 14).