Clarifications on Tenant retention policies & shared mailboxes‎

[Manoj Karunarathne]

Hi Folks,

This is probably not the ideal hub to post this question but couldn't think of anywhere else.

This is bit of a licensing clarification question where I am looking for a definitive answer, specifically two scenarios as below.

Q1. Does a shared mailbox fall under the retention of a policy in the Security & Compliance Centre, even when it's not licensed?

Q2. Does it matter if the shared mailbox was licensed in the past? Ie, it might've gone above 50GB so was assigned an EOP2, reduced the mailbox size then removed the EOP2. Or the other scenario, an account for an employee was licensed, they left the organization and their mailbox was converted to a shared mailbox but still under 50GB so does not require an EOP2 license.

[#2]

I dont remember Microsoft addressing this anywhere, but I'd wager they'd want Plan 2 or equivalent license.

[#3 · Accepted solution]

Apparently I had to reach out to Microsoft support to get these verified. Sharing as it might help others who are looking for the same.

Ans1: Yes, Shared mailbox fall under the retention of a policy in the Security & Compliance Centre, even when it's not licensed.

Ans2: Shared mailbox can store up to 50GB of data without assigning a license to it. After that, you need to assign a license to the mailbox to store more data. For more details on shared mailbox licensing, please see Exchange Online Limits. When a shared mailbox reaches the storage limit, you'll be able to receive email for a while, but you won't be able to send new email. Then, after that, it will stop receiving email. Senders to the mailbox will get a non-delivery receipt.