Hi Tim Have you tried telnetting from the various points to the next and sending an smtp mail manually - when I have something in the chain giving gip I find this the most effective way of diagnosing where the issue lies. Hope that helps Simon
-----Original Message----- From: Boswell Tim [mailto:[EMAIL PROTECTED]] Sent: 04 December 2001 13:05 To: MS-Exchange Admin Issues Subject: .biz addresses Ex55 SP4, NT4 SP6a I'm having problems with users being unable to send to mail addresses in the .biz root domain. It seems pretty obvious that somewhere, somethings not configured to allow .biz through. The problem I have is that every server in the equation here is looked after by different people, all of whom say their server is fine, and resolving the DNS/MX without problem. So here's the scenario: NDR: (Names have been changed to protect...something...) C=US;A= ; P=Exchange ;lSERVER1-011129123354z-5796 ms exchange :ims:exch:site:SMTPSERVER 3550 (0009009AA)550 5.1.2 unknown host or domain SERVER1 - Users mail server SMTPSERVER - Server with the SMTP connectors/IMS on MAILHUB - VMS Server where SMTPSERVER sends everything. After MAILHUB, mail goes through MessageLabs for virus scanning. SMTPSERVER's admin is saying the NDR is being generated because MAILHUB isn't correctly configured for .biz root domains, and that SMTPSERVER does no DNS lookups at all. MAILHUB's admin is saying that Exchange is delivering the NDR, hence it's exchange that's got the problem. MessageLabs say they can handle .biz without problems. I know it's not a lot to go on, but can anyone give me any idea as to where the problem lies? The problem with my situation is that whoever has the problem has to do work if they admit it, and blaming someone else is a lot easier for everyone except me, who has to return to the users with a fixed email system! All help, as always, is appreciated Tim 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