In a mixed Microsoft Exchange Server 5.5 and Exchange 2000 Server organization, when an Exchange 2000 user sends an e-mail message to a mail-enabled Exchange Server 5.5 public folder, the Exchange 2000 user may receive a non-delivery report (NDR) that is similar to the following:
The following recipient(s) could not be reached:
1i491111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
111111111111111111111111111111111111111111111111111111111111111111 on 5/22/2001 11:19 PM
The format of the e-mail address is incorrect. Check the address, look up the recipient in the Address Book, or contact the recipient
directly to find out the correct address.
<interop42.Valdiviadom.extest.microsoft.com #5.1.3>
When an Exchange Server 5.5 user sends an e-mail message to the same mail-enabled Exchange Server 5.5 public folder, the mail is delivered correctly.