Unexpected Microsoft Defender for Office 365 License Requirement for Shared Mailboxes
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! https://office365itpros.com/2025/08/11/microsoft-defender-for-office-365/
Can't add shared mailboxes
Hi everyone I have an M365 Business Tenant with just one Exchange Online Plan 1 license active and one shared mailbox. The license I use for my locally installed Office Apps is from a M365 Family Plan. I can fully integrate my account with the EXO license but can't add the shared mailbox as seen in my screenshot. Is this due to the licensing through M365 Family? Does this disable the functionality to add shared mailboxes? The shared mailbox can be added in OWA and on mobile but not in my Outlook client. Thanks for any advice.
Tips/resources on managing Shared Mailboxes in New Outlook?
Hello In the New Outlook Shared categories are no longer available on a Shared mailbox. At each and every client I have they rely quite heavily on shared mailboxes for client interactions. Shared categories are used to distribute work in the team and reach consensus on who follows up. This is no longer working in the New Outlook. This makes centralized external communications via Outlook impossible. For small organisations, other software used by corporates is often seen as overkill. Teams is not an option given the fact that there are known external users and unkown users that you want to enable to reach the organisation in a simple and friendly way (Forms are not seen as customer friendly, nor Chatbots) What solutions would you suggest?Users sending direct messages to shared mailbox
We have users are sending direct messages to a shared mailbox in Teams. I've checked Power Automate incase there was an obvious fix but it seems to be things like "if you are mentioned in a Team or Channel" unless I've totally missed it. Perhaps setting up a Power Virtual Agent might be a workaround but it seems like overkill. I was wondering how everybody else deals with this isssue? Thanks!Comparing Outlook Groups to Shared Mailboxes (2022 Edition)
Outlook groups and shared mailboxes both help small teams work with shared email. The decision as to which to use depends on the exact needs the team has. Some recent changes made by Microsoft to allow users to create new folders and rules in group mailboxes might tilt the decision towards group mailboxes, but shared mailboxes still offer lots of potential. https://practical365.com/outlook-groups-vs-shared-mailboxes/
How slot booking works in Microsoft Bookings
Hi, In Bookings, I have created 1 calendar for each of my customers. I would like associate only 1 shared mailbox for all these calendars. When I add a shared mailbox in the staff of 1 calendars, it appears as a guest and I don't have access to calendar availability information. I also tried to add a O365 group in staff but it's the same behavior. This means that when a customer reserves a time slot in one calendar, the same time slot is not blocked on the others calendar How slot booking works in Bookings ? Other question : when I associate a shared mailbox on one service, regularly the shared mailbox employe disappear from service. Ii's a bug ?
Unable to delete Shared Mailboxes
We are trying to remove a shared mailbox to convert them into Groups, however we are getting this error message. Error: An Azure Active Directory call was made to keep object in sync between Azure Active Directory and Exchange Online. However, it failed. Detailed error message: Another object with the same value for property proxyAddresses already exists. RequestId : xxxxx The issue may be transient and please retry a couple of minutes later. If issue persists, please see exception members for more information. Can anyone help us why are we getting such error and how to successfully delete the shared mailbox. thank you so muchBest route to creating a permission-limited shared calendar in Outlook and Teams? Tearing hair out!
Hi there, I've got a conundrum which I can't easily find an answer to. We're trying to get Teams rolled out and one of the really good tools to draw people in would be a shared annual leave calendar displayed in a Teams Tab. But this is where it gets problematic. What I really want to achieve is to have an calendar address where staff can send dates via a meeting invite etc eg to "annualleave@xxxxx.com" This calendar would be administered by the admin, who only wants other people to have read permissions. It could then be shared and read in other people's Outlook calendars. My first approach was to create a Shared Mailbox with the mailto:annualleave@xxxx.comaddress. This works fine in Outlook and does everything we need. So far, so good. But how then do we get this calendar to also appear in Teams as a tab so that people can view it in Teams and not just in Outlook. I'm dealing with some really technophobic people so I want to minimise learning. Teams is going to be enough of a struggle. Is there a way to get a Shared Mailbox calendar to appear in Teams? If not, is there another solution eg using Power Automate to duplicate events, or to lock down permissions on a Group calendar. My understanding is that a Sharepoint Calendar is no good as it won't actively sync across to Outlook in all its forms. It feels a bit much to create an O365 group for this purpose, and in any case it would not be possible then to lock down permissions to Read, as I understand it. Has anyone got any ideas? The internet seems startlingly quiet on this one! Rich
