get exchange to send mail to office 365 for same domain

my domain has exchange 2003 and office 365.  how do I get exchange to send mail to 365 if the account is not found locally.
Who is Participating?
IvanConnect With a Mentor System EngineerCommented:

since you don't have hybrid deployment (exchange 2003 don't support it), if you have configured at office 365 same public domain that you have on exchange 2003, then your solution is forwarding.

You have to configure office 365 exchange for domain,  to be internal relay, and not authorative, and then create new send connector for that domain to point to exchange 2003.

This will get email from office 365 users to your users on exch 2003.

Then on exchange 2003, you need to make sure that you have mailboxes for all users, including office 365. This will get email from your on-premiss users to office 365 not to be rejected.

Then configure forwarding, so that when mail is sent to user that is on office 365, it will be forwarded to it, but via email address
It cant be send to it via because exchange 2003 will send it to it self, and it wont get up to the cloud.
You point MX to your on-premessis exchange (as it was before).

Other solution would be almost the same, to point MX to office 365, configure 365 exchange as internal relay, configure send connector to exchange 2003 server for that domain,and tell your users (that are on exchange 2003) that when they want to send email to users on office 365, to send it by their address

I'm not sure will exchange 2003 accept email in this second configuration tho, because email is coming from same domain hosted on 2003, but he does not have those users..

Vasil Michev (MVP)Commented:
Just use the targetaddress attribute to point the mail to the address. If there is no user account, create one, or a mailuser/contact.
dgauwitzAuthor Commented:
thank you for your prompt reply and good info
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.