Hi, We have two sites (production and DR sites). The production site has one Exchange frontend server and exchange backend server. the DR site has one exchange 2003 frontend server and exchange backend server. All users are located on the production site. I have two routing groups (Production and DR) created and two SMTP connectors created. In case the production is down, mails will route to DR site. It works fine when that happens. Now, we have issue. sometimes mails are routed to DR site to go out. Is there a way to prevent this if the production server is online and we do not want mails route out to DR site? (Exchange 2003 SP2) Thank you.

Set the cost on the DR site to a higher value than the cost on the Production site. Exchange will attempt to use the lowest cost route that is available.[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

Thanks for your help. I changed all SMTP connector and routing group connectors in the DR site to cost 100 (which is higher than production site cost 1): But, some mails are still route to DR site's SMTP connector out. What might I miss?