Software

I have two separate DC in two different location both having its own AD and users. On both i just install exchage server and these server is configure to routea receive traffic on domain
domain = mycompany.com
means both exchange mail setting having entries of live mail exchange ip etries.

how both side different users sharing same domain name and
I dont want to user domain like
location_1.mycompany.com
location_2.mycompany.com
only with same name and users query emails for user@mycompany.com

I also establish list of users on both side like no user ids duplication on both side....

now i will configure exhange that if my location no.1 server download/get an email of user who reside at location2 ...that....this email auto forward to location2 server ...or....after receiving of email if email id not exist then forward to 2nd location server...

plz give me guideline regarding this matter...asap..