Hi All, I need to understand about what goes on when company A acquires company B while both have different Exchange Organizations. For Instance, Company A has acquired Company B and wants the Company B users to use @CompanyA.com as their e-mail address when sending and receiving. At Company B, this can be achieved through additional SMTP Addresses using Recipient Policy or manually adding SMTP Addresses to users. But at Company B, in order to send and receive e-mail using @CompanyA.com, what would be required at both Company A and Company B. Kindly, enlighten. Thanks in advance.

Hi Geek, For this issue, you can use SMTP namespace sharing to achieve the goal, please refer to the following documents: Supporting Two SMTP Mail Domains and Sharing an SMTP Mail Domain with Another System http://technet.microsoft.com/en-us/library/aa997194(EXCHG.65).aspx Exchange 2007 SMTP Namespace Sharing and Different Relay Domain Types http://www.msexchange.org/articles_tutorials/exchange-server-2007/planning-architecture/exchange-2007-smtp-namespace-sharing-different-relay-domain-types.html If anything is unclear, please feel free to let me know. Best Regards, EvanPlease 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.