A change to Teams makes it easier for users to share files in federated chat. Sounds good, but Microsoft planned to overwrite existing tenant controls to make the feature work, and that’s wasn’t so good. That issue is now resolved, but the real question is whether Microsoft 365 tenants want users to share files through federated chat. I’m not so sure and would control this facility tightly. Apart from anything else, you might need some more MDO licenses to protect against possible infection.
Microsoft Defender for Office 365 (MDO) can detect and quarantine email containing prompt injections. Shared mailboxes might need MDO Plan 2 licenses if they receive email from external domains. This requirement existed before MDO introduced Prompt Injection Protection, but the advent of the new capability is another reason to check mailbox licensing, especially if your tenant uses Copilot. We have a script to help!
Shared mailboxes might need Microsoft Defender for Office 365 licenses, but how do you identify how many licenses? We use PowerShell to do the job by analyzing external email sent to shared mailboxes. If a mailbox receives external email, then by definition the mailbox receives benefit from MDO, and that’s the test for requiring a license.
A question about shared mailboxes brought up the topic of licensing requirements when a tenant has Microsoft Defender for Office 365 (MDO). The news is not good. Once MDO is active, every shared mailbox needs an MDO license, and every user mailbox must also be licensed for MDO (those with E5 licenses are covered). At $5 per month, those MDO licenses can ramp up to a considerable cost. Ouch!
