when send email, the email route to other mailbox server before go to internet

There are 2 AD site (US, Japan) in my environments.  Each AD site, include 2 Exchange mailbox servers.  I found that when I use US email account send email to Japan users and cc Internet users, the email submit to mailbox server in Japan, then via the Japan mailbox server to internet. 

And when I use Japan email account send email to US users and cc Internet users, the email submit to mailbox server in US, then via the US mailbox server to internet. 

When I use US account send email to US user and cc to Japan users and Internet user, the email will submit to the 2nd mailbox server in US, then, only Japan user email will submit to Japan mailbox server, and the internet email will send directly to internet on the 2nd mailbox server in US. 

May I know, can I change this behavior to:

when I use US account to send email and the mail include only Japan users and Internet user, the internet email will send out directly from the mailbox server that the US account sitting in and do not submit the internet email to Japan mailbox server?

Thanks.