Discovering Org-Wide holds
Get-OrganizationConfig | Select -ExpandProperty InPlaceHolds
We are interested in the holds that start with “mbx”.
Excluding Org-Wide holds from inactive mailboxes
Set-Mailbox -Identity <PrimarySmtpAddress> -ExcludeFromOrgHolds "mbx9696958xxxf74ecda8a40aef97edd2c2:1", "mbx19200b8xxx8442529be070dae2fd54d3:1"
# mbx ids in the command are just for illustration
To remove all org-wide holds from a mailbox, run Set-Mailbox and pass the ExcludeFromAllOrgHolds parameter:
$mbx = Get-Mailbox -Identity <PrimarySmtpAddress>
Set-Mailbox -Identity $mbx.DistinguishedName -ExcludeFromAllOrgHolds