This isn't a recipient unknown message. The NDR states "550 not local host jr.com, not a gateway" so whatever mail server they were communicating with doesn't think it is responsible for jr.com.
Your mx records sit behind a PIX running the SMTP fixup protocol so I can't get far enough in an SMTP conversation to see if one of them might be busted... or they could have had a bad mx lookup or they could have been relaying to some other internal server on their side which was having a bad day. Only their SMTP protocol logs could tell them that. > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:bounce- > [EMAIL PROTECTED] On Behalf Of Aristotle Zoulas > Posted At: Thursday, May 10, 2007 9:00 AM > Posted To: swynk > Conversation: unknown user > Subject: unknown user > > We have a valid user on our system. Someone from outside the company > sent an email to him and got his bounceback: > > > > Sent: Wednesday, May 09, 2007 5:07 PM > To: [EMAIL PROTECTED] > Subject: Undeliverable Mail > > Unknown user: [EMAIL PROTECTED] > > RCPT TO generated following response: > 550 not local host jr.com, not a gateway > > > > I added the "TO" and the "FROM" for privacy purposes. > > > The recipient receives a ton of email every day without any problems. > > Why would this sender get this bounceback? > > > Running Exchange 2003. > > > TIA > > > Aristotle Zoulas > > _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Web Interface: http://intm-dl.sparklist.com/read/?forum=exchange To subscribe: http://e-newsletters.internet.com/discussionlists.html/ To unsubscribe send a blank email to [EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED] To unsubscribe via postal mail, please contact us at: Jupitermedia Corp. Attn: Discussion List Management 475 Park Avenue South New York, NY 10016 Please include the email address which you have been contacted with.
