Forum Discussion
Archive mailboxes during migration to O365
Migrating from on premise exchange to Office365.
Active mailboxes will use Business Premium and Essentials licenses with annual commitment (33 users total)
There are some mailboxes for ex-employee that need to be preserved indefinitely. (27 total mailboxes)
So far with my research I can import these ex-employee mailboxes and then use either a litigation hold or a retention policy to do this.
So to do that I have read that I need to license the mailbox with a Exchange online plan 2. Or that I could use a Business Premuim/Essentials license with a $3 add-on for Exchange Online Archiving license. But once i have the mailbox with the hold or retention policy I can remove the licenses. I am uncertain of all of this. And since my Business premium/essentials licenses will have annual commitment would I also be commited to the $3 per month on an annual basis.
Just trying to figure out the best strategy to do all of this with the lowest cost of licensing. I was thinking of migrating the 27 mailboxes from the ex-employees and configuring the hold or retention. Then delete these account and apply the licenses to the account that will be active.
5 Replies
Many orgs use a Shared mailbox to hold ex-employees - as they don't consume a license.
But this doesn't store the mailbox in an 'in-changed' state. As a result many recommend the inactive mailbox as the desired way to store ex-employees mailboxes.
There is a good write-up here : https://practical365.com/exchange-online/shared-mailboxes-vs-inactive-mailboxes-departed-users/
- Hi Wes,
As Cian said you're definitely on the right track. If you're using Business Premium/Essentials then Exchange Online Archiving is required to be able to turn on litigation hold.
Once litigation hold is on, delete the user and they'll be kept as inactive mailboxes for eternity. Some people also use Shared Mailboxes if you still need route-able email and people to log directly into the ex-employee mailboxes
EXOP1 + EOA comes out a little cheaper than EXOP2.
The trick here is to get yourself CSP provider who can supply the licensing at retail or cheaper (if enough seats for them to give you a discount).
Most CSP providers can supply you the licensing at the annual cost price but on a monthly rolling which allows you to be flexible and in your case only take a month hit for the ex-employee's. - Longvines@outlook.com
You are on the right track Wes. You will need those licences you have mentioned, assigned to the ex-employees as part of your migration. These are needed for as long as you need to apply the Litigation Hold or an Office 365 retention policy to take place. After this, you can delete the user accounts in question, then you can assign these licences once that all goes through, to your active users.
"To make a mailbox inactive, it must be assigned an Exchange Online Plan 2 license so that a Litigation Hold or an Office 365 retention policy can be applied to the mailbox before it's deleted. Exchange Online Plan 2 licenses are part of an Office 365 Enterprise E3 and E5 subscriptions. If a mailbox is assigned an Exchange Online Plan 1 license (which is part of an Office 365 Enterprise E1 subscription), you would have to assign it a separate Exchange Online Archiving license so that a hold can be applied to the mailbox before it's deleted. For more information, see Exchange Online Archiving."
"The license associated with the deleted Exchange Online mailbox will be available after you delete the corresponding Office 365 user account. You can then assign that license to another user."
https://support.office.com/en-us/article/Overview-of-inactive-mailboxes-in-Office-365-1fbd74e8-7a60-4157-afe8-fe79f05d2038
https://support.office.com/en-us/article/Manage-inactive-mailboxes-in-Office-365-296a02bd-ebde-4022-900e-547acf38ddd7
