Hello all. I?m having a problem with no solution by the moment. I have two servers with Exchange 2000 in the same domain. Server 1 users can send to server 2 users, but when server 2 users reply or send a message to server 1 users they receive the following message: You do not have permission to send to this recipient. For assistance, contact your system administrator. <domain.com #5.7.1 smtp;550 5.7.1 Unable to relay for XXX@xxxxxxxxxx> If you shutdown server 2 and send a message from server 1, the message wait to server 2 for delivery, but if you shutdown server 1 and send from server 2, the error appears immediately. Any idea? Thanks in advance. ===================== Use the below link for Archives, and to set your preferences. http://thethin.net/exchangelist.cfm