A short guide here on how to move Resource mailboxes with ease using PowerShell, this also can be done with any mailbox user.
Pretty much follow the commands like so, ensure you know the Alias of the Mailbox you are moving, your Server FQDN and your Target Domain in Office 365.
$LiveCredential = Get-Credential
Import-PSSession $Session -Prefix O365 (Prefix is very important, you need to specify a Prefix so Exchange and Exchange Online can determine who the command is for and to process)
Now you can check the progress, using this command.
get-o365moverequest “MAILBOXALAIAS” – It Will show if it has failed, In progress or completed.
But what if it fails? You can view in your Exchange Management Console. Click under Office 365 Hybrid, and than move requests. You can view the logs and determine the issue. Some of the issues I had were with corrupted items. Otherwise running the above is usually fine
Run the following,
get-o365moverequest “MAILBOXALIAS” | Set-Moverequest -baditemlimit 10
Check the Progress again,
Hope this helps, let me know if anything doesn’t seem right by posting below =)