Hi Folks, First of all sorry for my bad English.. any pointers on my below question would highly appreciated...thanks in Advance.. A brief overview : Currently A company merging with B & C. Domains A.com, B.com & C.com A.com uses exchange 2007 for email,like B uses exchange 2010 & C uses Exchange 2007. We have planned to use B.com as smtp domain & configured internal relay domains as A.com & C.com & create rule hub transport server to change the name-space for A.com & C.com to be B.com for outbound email.. Our Moto to accomplish : When mail delivers from user@A.com its domain gets changed to user@B.com...the receiver receives, now when he / she replies to the mail, it should be delivered to the sender i.e user@A.com but changed to user@B.com (Transport rule) When the receiver replies ..he/she will reply to user@B.com but when it reaches the exchange hub transport it should again be routed to user@a.com. Well this can be accomplished by creating contacts for user@a.com as user@b.com but is there any other way which can help to resolve this without creating additional contacts.

Hi, Need some clarification, A.com & C.com the whole routing is handled by B.com both incoming & outgoing & all these domain have tow way trust, in that case you can add B.com as primary email address in both domain, A.com & C.com as secondary in there respective domains, that way if a mail arrive for A.com it will be received & when they replay it will have the email address as B.com since it primary. Kindly let me know if i understood it wrongly & revert if the solution is not feasible. Ripu Daman Mina | MCSE 2003 & MCSA Messaging