We want to coexist a pop3 hosted email service with Exchange. we are going to migrate the pop3 users to Exchange, however i dont really know how to coexist migrated users with non migrated users talking only a mail flow level. if i create an accepted domain i hace 3 choices: authoritative: this means that if a mailbox does not exist in the exchange org the message will be rejected internal relay: if the mailbox does not exist in the exchange org, email will be route to a different mail system or forest external relay: this is the best that fits the enviroment, however external relay does not allowed to create email address policies and we need to maintain the same smtp address and domain not sure if using internal relay i can route emails outside to the exchange org and going through the internet. thank youCapecol MCSA - MCTS Exchange Server 2007 - 2010 - MCITP Messaging 2010 - MCT Blog: http://capecol.spaces.live.com/default.aspx

Hi, You need to configure the sharing SMTP name space in Exchange 2007 servers. More information: http://www.msexchange.org/articles_tutorials/exchange-server-2007/management-administration/accessing-shared-email-addresses-part1.html For example, if your external MX record is pointed to exchange 2007 server and you have configured the STMP name space in exchange 2007 server, then the Internet mail will first arrive at your exchange 2007 server. Exchange server will check if this email is belong to the users in exchange organization. If not, this email will be routed to the SMTP service of your POP3 server. Gen Lin TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com

Hi, Is there any update?