About:

In case of having ‘ in the email address – example: SMTP:Heath.O’Brien@ridley.com.au – I will need to fix it.

Need to remove the ‘ from the address

Steps:

In AD, locate the user, properties, Change the first name and last name to remove the ‘ from the name itself and leave the display name as it is.
In AD, locate the user, properties, Attribute editor, and double click on proxy address

Remove the SMTP that has the ‘ in the address. Make sure that there is another SMTP with the correct address. Notice SMPT mean primary address. smtp means alias address. If there is sip attribute also, make sure it is modified to the new address without the ‘ too.
Then you wait until it is synced with O365 or force sync with dirsync server.
Check on O365 portal and make sure that the new email address if the primary now.
Login to O365 portal, locate the user, and click edit on Username section
Confirm that the primary address has changed to the new one
Then you need to change the remote route address to .mail.microsoft so that sending and receiving emails will be to the correct address
Connect PS to exchange on-prem server
Then type this command:
- Set-RemoteMailbox -Identity “doconnor” -RemoteRoutingAddress ‘doconnor@RidleyOnline.mail.onmicrosoft.com’
- You will need to modify the paramater to the new user’s details.
Then you wait until it is synced with O365 or force sync with dirsync server.