hello friends I have the following architecture 2 a postfix mail server (2.2) and exchange 2007 both in the same domain but different MX. All mail from outside to pass through the exchange, the mailbox gets its responsibilities and who do not, send the following mail server (postfix). But the emails from the LAN is not so, if the client has their mailbox in postfix, the mail is addressed to the postfix server and if the mailbox is on exchange this look for the exchange server. The problem is that if the account has a mailbox in postfix tries to send an email to an account that has a mailbox in the exchange automatically show him the error 550 it will look in your users table in the server account postfix and there has not been set as the error. My question is how to configure postfix to determine this email it does not belong to me and if I do not own search in the following mail server
