Hi all, I have a problem connecting 2 servers within the same site. One of them is our old exchange 5.5 server and the other one is one which has exchange 2000.After installing w2k on a new server and then running setup with /forestprep and /domainprep I installed a new exchange 2000 server. This was installed into an existing exchange 5.5 site.The exchange 5.5 admin program recognises the 2000 server and true vice versa as well. After this I tried moving a user's mailbox onto the new 2000 server and this worked fine. However when I try to send a mail from a user on the old server to this user it comes back straight away with a message saying "A required directory operation was unsuccessful". After this I moved the mailbox back to the old server it works fine. Also I tried creating a new user on the exchange 2000 server and the user appears in the GAL. But when I try to send a mail from the old server to this user it comes back with a message saying "The recipient name is not recognized". I have checked out the service account permissions as well as done a RPC Communication check which is successful. Within the same server i.e e2k to e2k users I can send email. Also this new e2k server is registered on our internal DNS as a mail exchanger but not on any external DNS. If I send a email to the user on his external address based on the e2k server it comes back undeliverable. The e5.5 server is registered on the external DNS. Do I need to make any changes to achieve this? Any help on this would be highly appreciated. Thanks in advance Milind Kale