I have two different forests a.com and b.com and both have all the roles CAS,Mailbox and Hub Servers installed on the same machine. I need to configure mail flow between both of these forests. Can anyone tell me what all I need to do make it possible? Best Regards, Parveen Email- prvpnr@hotmail.comBest Regards, Parveen Email- prvpnr@hotmail.com

In A.com, create a send connector for the domain name b.com and point it to a HT server in b.com. Do the reverse in B.com. On the hub transport servers receiving the connection, allow the relay from those servers. That should do the trick.Casper Pieterse, Principle Consultant - UC, Dimension Data South Africa, Microsoft Certified Master: Exchange 2007 / 2010

Hi Parveen, From your description, you would like to enable cross-forest communication. Create Send connector from a.com to b.com. Create Receive connector for a.com to receive mail from b.com. Modify the authentication method that is used for this receive connector. For detailed, pleas see Microsoft official article. Configuring Cross-Forest Connectors: http://technet.microsoft.com/en-us/library/bb123546(EXCHG.80).aspx Best regards, SerenaPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.