I just installed Exchange 2010 onto my domain and moved over from my 2003 exchange server 2 mailboxes that are not being used by the company so are really just test mailboxes. I can send email through the internet and internally to exchange 2003 users. But I cannot send email from exchange 2003 server or from the internet to the 2010 exchange mailbox user. I can however send internal mail back and forth with the exchange 2010 users but only to each other. I have tried everything from recieve connectors to reinstalling rollup 4v2. really am stuck here and could use some help. The 2010 exchange server is running on 2008 r2 and the 2003 exchange is running on windows 2003 server.