Important: Microsoft has decided not to go ahead with the plan. One of the advantages of gathering at Ignite is the chance to have some in-depth conversations about topics. Microsoft was gracious enough to understand that they need to do some more work to understand how tenants use inactive mailboxes before they should introduce new licensing rules. They have confirmed that this change will not be going into effect on October 1 as planned.
We have thought about this a lot over the past few years and always wondered when Microsoft would bring in the requirement to license inactive mailboxes. Up to now you could technically convert a user mailbox to shared, and/or place the mailbox on legal hold and then remove the license. It would retain the data and allow discovery searches.
From October 1st 2017 Microsoft introduces Inactive Mailbox Licenses. When your subscription renews after that point then any Inactive Shared Mailboxes, Teams and Groups require a license. (i.e. those mailboxes you’ve placed on legal hold and want to retain but that don’t have a license) The new SKU is expected to be US$3 per licenses (£2.50) and includes the legal hold capability, unlike Exchange Online Plan 2 which some customers have used for this purpose.
For Teams and Groups as long as at least one user in the tenant has a valid E3/E5 subscription then compliance is available for all teams/groups and you don’t need to license the team or group separately (in order to encourage usage) unless you want more storage or other features that E3/E5 grants.
If you’re worried about your licensing impact, then please contact us and we’ll talk you through the changes. We can potentially also assign a 25 license, 1 year trial via our Cloud Solution Provider (CSP) status to help soften financial impact
We hope that helps!