Looks like DNS issue to me.. Did you try to do a NSLOOKUP to see if you can resolve their domain name?
-----Original Message----- From: Mathews, James E. [mailto:[EMAIL PROTECTED]] Sent: Friday, December 07, 2001 2:51 PM To: MS-Exchange Admin Issues Subject: Client not receiving email from us but can from any other site Exchange 5.5... Outlook 2k client We are trying to send email to one of our clients. they can send to us without problem. I can send to them from an external email address (yahoo) with no problem. After we send messages we do not receive a "undeliverable reply". Here is my thoughts let me know if you guys have any idea. Since we do not get a undeliverable reply it appears that the email is going someplace. any email I send to their name does not get bounced back. example if I send to [EMAIL PROTECTED] (don't want to use their email address hope you don't mind) I receive no undeliverable message. if I send to any other email address that is wrong I get a bounce back. if I send to a yahoo account that does not exist it bounces it back. We are on a sprint network so I though maybe sprint is not able to resolve their name correctly so I called sprint had them send an email and it go through fine. so I have no idea what the problem could be. Please help. Thanks James List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm