We are working on analysis/development activities for our archiving solution which is planned to support Hybrid MS Exchange as a source. To achieve communication with the exchange server, our application uses the Outlook profile through MAPI. In the profile, we have added the email of the Exchange Online user. Our solution works fine if the archival source is an exchange online user mailbox. When we changed the source to an on-prem user mailbox, our application failed to process the mailbox. Hence we tried the below steps:
1. Created profile with online user email (say email@example.com)
2. Added O365 license and gave full access on the on-prem user (say firstname.lastname@example.org) to email@example.com
3. Added firstname.lastname@example.org mailbox manually to the created profile and logged in with online-user creds in windows creds pop-up
After performing the above steps, our application was able to process the on-prem user mailbox. We would like to know if the above is the right approach for establishing a connection between online and on-prem users and mailboxes? Or is there any other approach possible? Please advice.