STEP #1 Allow mail to route between servers
1. Add a route on the Exchange server to route @corp.<companyname>.com
2. On Domino make a new domain document for this address.
3. On the Domino server route outgoing mail to your exchange server
4. create test user account on exchange
4. create an “aliase” test user account account with email address of @corp.<companyname>.com
5. set the “real” exchange account to forward to the “aliase”
6. create test user account on domino serve
7. add exchange server IP/name on the server config smtp tab – local internet domain smart host lookup.
8. Create Exchange Address book for migration.

Here is what is happening.
Email comes into exchange for Joe.Doe@mycompany.com. Exchange passes this email to the aliase account which tells exchange to forward the email to joe.doe@corp.mycompany.com. Exchange has a route telling it to deliver these to <yourdominoip>. Domino gets the request and accepts it because it have a domain document. It then checks and sees a joe.doe reference.

When user sends to a jill.doe@mycompany, it won’t find her in domino, but because of step #7, it will pass it to exchange for processing.

STEP #2 Mail migration
We used BinaryTree CMT migration

Step #3 group mailboxes/TeamMail boxes
We used the OPENNTF Team Mail Box utility for shared department mail.

Step #4 Final cutover
Power off exchange
Update mail filter with Domino IP
Remove Exchange references from Domino