Question : Undeliverable: recipient name not recognized -- Exchange 5.5

Hello,

I have an issue when trying to send an email to a certain domain from our Exchange. I am using Exchange 5.5 on a Win NT 4.0 machine. We use Outlook Clients.   I am tring to e-mail an organization that has a .us domain. I have no problem receiving email from them but cannot send/reply back to them. I am able to email them from other outside addresses (@gmail, @yahoo, etc..). I also cleared my DNS servers cache file, which had no success. Here is a copy of the bounce back:

Your message did not reach some or all of the intended recipients.

      Subject:      Test
      Sent:      3/26/2008 4:45 PM

The following recipient(s) could not be reached:

      '[email protected]' on 3/26/2008 4:45 PM
            The recipient name is not recognized
      The MTS-ID of the original message is: MYCOMPANYINFOHERE

Based on a previous post, I'm not sure if I am on some sort of blacklist, or if it is an Exchange 5.5 issue. I attempted to do a telnet and send an email from their server, but I get this error at the rcpt to: command:

rcpt to:[email protected]
550 btr.bellsouth.net[68.213.xxx.xxx]>: Client host rejected: Please use your local SMTP server

Any help would be greatly appreciated.

Thanks.

Answer : Undeliverable: recipient name not recognized -- Exchange 5.5

This message does not necessarily indicate that the recipient is invalid, but rather that the MTA does not recognize the address type as a deliverable type. Make sure the recipient address type is valid. You should verify that the address spaces for the required connector contain at least the type of address (X.400, SMTP, SNADS, MS, and so forth). This is done through the Address Space property tab of the connector responsible for routing the mail to the recipient.

Try the following:

http://support.microsoft.com/kb/133403