This script helps by creating or recreating a supported state for hybrid Exchange.

If on-premise Exchange mailboxes were migrated with third party tools to exchange online, this script can merge the "old" on premise Mailboxes with the current Exchange online Mailboxes. 

The script is editing the on-premise mailboxes to become remote mailboxes, sets the routing address and merges the Exchange GUID from the online Mailbox with the on-premise one.

The script connects to Exchange online and the following criteria for the user must be considered:
– The specified account requires the appropriate permissions to read the required information from Exchange online.
– The script currently does not work with MFA. therefore, it should be an account that is not MFA enabled.

This script does not change any configuration on Exchange online. Only on-premise modifications are made.

Detailed documentation on the script and real world cases can be found at https://www.msb365.blog/?p=3966.

       .CHANGE LOG             

V0.10, 2019/12/27 - Initial version             
V0.20, 2019/12/30 - Bug fixes, User input           
V0.80, 2019/12/31 - Add error handling             
V1.00, 2020/01/04 - Final version V1             
V1.01, 2020/02/12 - Bug fixes, msExchRecipientTypeDetails modified to "1"