1. Is active database and passive database only replicate log from mailbox server to another mailbox server? 2. If more mailbox server to be implement in a DAG will slow down the Exchange perfomance? Anything that need to be consider? 3. If a Hub transport forward an incoming email to mailbox server after process. Which mailbox server will recieve an email, or all of the mailbox server in DAG will receive?

1. Database replication is between mailbox servers, yes. 2. I believe that it is safe to assume that more resources will be consumed the more databases copies you have. I'm not sure of the amount; you might consider modeling this using the Mailbox Role Calculator. http://gallery.technet.microsoft.com/Exchange-2010-Mailbox-Server-Role-/ 3. The e-mail message is delivered to the mailbox server on which the target database is active. The changes to the database caused by the delivered message are replicated to the other copies afterward.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

1. Database replication is between mailbox servers, yes. 2. I believe that it is safe to assume that more resources will be consumed the more databases copies you have. I'm not sure of the amount; you might consider modeling this using the Mailbox Role Calculator. http://gallery.technet.microsoft.com/Exchange-2010-Mailbox-Server-Role-/ 3. The e-mail message is delivered to the mailbox server on which the target database is active. The changes to the database caused by the delivered message are replicated to the other copies afterward.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."