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Summary: Microsoft 365 plans offer shared mailboxes, allowing multiple users to send and receive emails from a common address. While they have advantages, these shared mailboxes have limitations, such as a 50 GB size limit. To address this, users can back up Office 365 shared mailboxes using tools like Kernel Office 365 Backup & Restore.

In Microsoft 365 plans, business accounts extend beyond individual users. Administrators can establish shared mailboxes, enabling multiple users to send emails from these accounts. These shared mailboxes, such as or, allow users to send messages anonymously, concealing the individual sender’s identity from recipients.

Numerous Office 365 users frequently express concerns about the necessity and process of backing up their shared mailboxes. While Microsoft’s technical support team may not address every query, this article aims to provide a comprehensive answer to this common question.

What are Shared Mailboxes?

A shared mailbox, established by the Office 365 administrator, facilitates multiple users in sending and receiving messages from a single address. This feature assists organizations in managing customer inquiries and serves as a repository for data migration from on-premises public folders./p>

Shared mailboxes are not linked to individual users; instead, they are configured to be accessible by multiple users, such as the Sales team, Accounts team, HR, and more.

When a message is sent from a shared mailbox, the recipient receives it from the shared mailbox itself, not from a particular user. While the administrator creates the shared mailbox, it doesn’t have a designated owner or password. However, users must have permissions granted by the administrator to access it.

Furthermore, shared mailboxes in Office 365 are cost-free and do not necessitate a separate license. However, certain limitations apply. For instance, a free shared mailbox is limited to a size of 50GB and cannot serve as a primary mailbox.

However, there are other limitations as well. So, let’s have a look at them:

Limitations of Shared Mailboxes

Now, as you know about Shared Mailboxes, it’s necessary to know its limitations as well:

  • It is absolutely free to use and doesn’t require a license, but users that access Shared mailboxes must be assigned with Office 365 licenses.
  • If you have Exchange Online Kiosk license, then you cannot access Shared Mailbox.
  • Every Shared Mailbox has a size limit of 50 GB, and if it exceeds that limit, then it needs to be licensed.
  • A shared Mailbox doesn’t have a Username or Password, and no one can sign into it directly. To access a shared mailbox, users need to sign into their own mailbox, and then open the shared mailbox.
  • It cannot be used to archive emails from a user.
  • It cannot be accessed using ActiveSync clients.
  • It cannot be used for Journaling.
  • It can only be accessed via Outlook desktop and Outlook Web client after the user mailbox configuration. And to access the shared mailbox via Outlook, you need to configure the user mailbox that has access to Shared Mailbox.

Considering the information mentioned above, you might be inclined to create a shared mailbox in Office 365. However, please note that only administrators have the privilege to create shared mailboxes through the Exchange Admin Center (EAC). To proceed, follow these steps:

  1. Log into your Office 365 Admin Center.
  2. Go to Exchange Online Admin Center, click Recipient
  3. Find the Shared icon and click Add.
  4. Enter the details for the Shared Mailbox and add users that will have access to view and send emails from Shared Mailbox.

Many organizations frequently surpass the shared mailbox limit in Office 365, necessitating the backup Office 365 shared mailbox data to avoid purchasing additional licenses. However, manual backup methods can be challenging. Hence, a third-party solution is recommended, offering a swift and secure Office 365 backup solution for shared mailboxes.

Kernel’s Office 365 Backup and Restore tool is a powerful solution designed specifically for backing up Office 365 mailboxes and restoring them within your Office 365 environment. This software allows you to efficiently back up every mailbox within your Office 365 account.


Shared mailboxes in Office 365 offer numerous benefits to users, but they come with a 50 GB storage limitation. To ensure data preservation, organizations should consider backing up their shared mailboxes in Office 365, a task efficiently accomplished through the use of Kernel Office 365 Backup & Restore software.