Public folders in Microsoft 365, Office 365, and Exchange Online (2023)

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Public folders are designed for shared access and provide an easy and effective way to collect, organize, and share information with other people in your workgroup or organization. Public folders help organize content in a deep hierarchy that's easy to browse. Users will see the full hierarchy in Outlook, which makes it easy for them to browse for the content they're interested in.

Note

Public folders are available in the following Outlook clients: Outlook on the web (formerly known as Outlook Web App), Outlook 2007 or later, and Outlook for Mac.

Public folders can also be used as an archiving method for distribution groups. When you mail-enable a public folder and add it as a member of the distribution group, email sent to the group is automatically added to the public folder for later reference.

Note

Public folders functionality of the Classic Exchange admin center experience is available in the new Exchange admin center as we continue to work on updated versions. If you're using Edge incognito and this page isn't working, enable the third-party cookies.

(Video) How to create public folders and public folder mailboxes in Exchange Admin Centre | Office 365

Public folders aren't designed for the following purposes:

For more information about public folders and other collaboration methods in Microsoft 365, Office 365, and Exchange Online, see Collaboration in Exchange Online.

For more information about public folder quotas in Microsoft 365, Office 365, and Exchange Online, see the service description articles Sharing and collaboration and Exchange Online limits.

For a list of public folder management tasks, see Public folder procedures in Microsoft 365, Office 365, and Exchange Online.

For more information about the public folder limits in Microsoft 365, Office 365, and Exchange Online, see Exchange Online limits.

Looking for the Exchange Server version of this article? See Public folders in Microsoft 365, Office 365, and Exchange Online.

Public folder architecture

Public folder architecture uses specially designed mailboxes to store both the public folder hierarchy and the content. The main architectural components of public folders are the public folder mailboxes.

Public folder mailboxes

There are two types of public folder mailboxes: the primary hierarchy mailbox and secondary hierarchy mailboxes. Both types of mailboxes can contain content:

(Video) How public folders work | Public folders in Office 365 | Public folders architecture and hierarchy

  • Primary hierarchy mailbox: The primary hierarchy mailbox is the one writable copy of the public folder hierarchy. The public folder hierarchy is copied to all other public folder mailboxes, but these will be read-only copies.

  • Secondary hierarchy mailboxes: Secondary hierarchy mailboxes contain public folder content as well and a read-only copy of the public folder hierarchy.

There are two ways you can manage public folder mailboxes:

  • In the Exchange admin center (EAC), navigate to Public folders > Public folder mailboxes.

  • In Exchange Online PowerShell, use the *-Mailbox set of cmdlets.

Public folder hierarchy

The public folder hierarchy contains the folders' properties and organizational information, including tree structure. Each public folder mailbox contains a copy of the public folder hierarchy. There's only one writeable copy of the hierarchy, which is in the primary public folder mailbox. For a specific folder, the hierarchy information is used to identify the following:

  • Permissions on the folder

  • The folder's position in the public folder tree, including its parent and child folders

Note

(Video) Exchange Online (Microsoft 365) - Zero to Hero - Exchange Online Public Folders - Part 7 - HINDI

The hierarchy doesn't store information about email addresses for mail-enabled public folders. Email addresses are stored in the directory.

Hierarchy synchronization

The public folder hierarchy synchronization process uses Incremental Change Synchronization (ICS), which provides a mechanism to monitor and synchronize changes to an Exchange store hierarchy or content. The changes include creating, modifying, and deleting folders and messages. When users are connected to and using content mailboxes, synchronization occurs every 15 minutes. If no users are connected to content mailbox, synchronization will be triggered less often (every 24 hours). If a write operation such as a creating a folder is performed on the primary hierarchy, synchronization is triggered immediately (synchronously) to the content mailbox.

Important

Because there's only one writeable copy of the hierarchy, folder creation is proxied to the hierarchy mailbox by the content mailbox users are connected to.

For more information, see Update the public folder hierarchy.

Public folder content

Public folder content can include email messages, posts, documents, and eForms. The content is stored in the public folder mailbox but isn't replicated across multiple public folders mailboxes. All users access the same public folder mailbox for the same set of content. Although a full text search of public folder content is available, public folder content isn't searchable across public folders (except when using the Content Search eDiscovery tool in the Microsoft Purview compliance portal) and the content isn't indexed by Exchange Search.

Considerations

Although there are many advantages to using public folders in Microsoft 365, Office 365, and Exchange Online, there are some things to consider before implementing them in your organization:

  • Outlook on the web is supported, but with limitations. You can add and remove favorite public folders and perform item-level operations such as creating, editing, deleting posts, and replying to posts. However, you can't create or delete public folders from Outlook on the web.

  • Although a full text search of public folder content is available, public folder content isn't searchable across public folders and the content isn't indexed by Exchange Search.

    (Video) Glide your public Microsoft folders to EXO!

  • You must use Exchange Online supported Outlook client or later to access public folders in Microsoft 365, Office 365, and Exchange Online.

Migrating public folders to Microsoft 365 or Office 365 and Exchange Online

When you migrate your public folders, you'll use a process called batch public folder migration. Batch public folder migration (or simply batch migration) creates a mailbox migration request for each public folder mailbox that will exist in Exchange Online. Using multiple requests means the migration will move along much faster because it's able to make more efficient use of available network bandwidth. It's also more reliable because it reduces the possibility of a single failure or bottleneck affecting the entire migration.

While batch migrations need to be started using the New-MigrationBatch cmdlet in Exchange Online PowerShell, the progress and completion of the migration can be viewed and managed in the EAC. Because the New-MigrationBatch cmdlet initiates a mailbox migration request for each public folder mailbox, you can view the status of these requests using the mailbox migration page. You can get to the mailbox migration page, and create migration reports that can be emailed to you, by opening the EAC in Exchange Online and navigating to Mailbox > Migration.

To use batch migration to migrate your public folders to Exchange Online, your legacy Exchange server needs to meet the requirements in the following list. If it does, and you're ready to start, check out Use batch migration to migrate legacy public folders to Microsoft 365 or Office 365 and Exchange Online.

Exchange supports moving your public folders to Microsoft 365 or Office 365 and Exchange Online from the following legacy versions of Exchange Server:

  • Exchange Server 2010 SP3 RU8 or later

See Use batch migration to migrate Exchange Server public folders to Exchange Online to migrate your Exchange Server public folders.

We recommend that you use batch migration instead of Outlook's PST export feature to migrate public folders to Microsoft 365 or Office 365 and Exchange Online. Microsoft 365 and Office 365 public folder mailbox growth is managed using an auto-split feature that splits the public folder mailbox when it exceeds size quotas. Auto-split can't handle the sudden growth of public folder mailboxes when you use PST export to migrate your public folders and you might have to wait for up to two weeks for auto-split to move the data from the primary mailbox. We provide batch migration instructions in Use batch migration to migrate legacy public folders to Microsoft 365 or Office 365 and Exchange Online and Use batch migration to migrate Exchange Server public folders to Exchange Online. However, if you've elected to do a PST migration and have run into an issue where the primary mailbox is full, you have two options for recovering the PST migration:

  1. Wait for the auto-split to move the data from the primary mailbox. This may take up to two weeks. However, all the public folders in a completely filled public folder mailbox won't be able to receive new content until the auto-split completes.

  2. Create a public folder mailbox and then use the New-PublicFolder cmdlet with the Mailbox parameter to create the remaining public folders in the secondary public folder mailbox. This example creates a new public folder named PF201 in the secondary public folder mailbox.

    New-PublicFolder -Name PF201 -Mailbox SecondaryPFMbx

FAQs

What are public folders in Exchange Online? ›

Public folders are designed for shared access and provide an easy and effective way to collect, organize, and share information with other people in your workgroup or organization. Public folders help make content in a deep hierarchy easier to browse.

Does Office 365 support public folders? ›

Although a full text search of public folder content is available, public folder content isn't searchable across public folders and the content isn't indexed by Exchange Search. You must use Exchange Online supported Outlook client or later to access public folders in Microsoft 365, Office 365, and Exchange Online.

Are public folders going away in Office 365? ›

Are public folders going away? No. Public folders are great for Outlook integration, simple sharing scenarios, and for allowing large audiences to access the same data.

What are the public folder permissions? ›

The user can view and move the public folder, create subfolders, and set permissions for the folder. The user cannot read, edit, delete, or create items.

What is the purpose of public folder? ›

Public folders are an easy and effective way to collect, organize, and share information with others in your department, or across your organization. You can use public folders to store any type of file or Outlook item. Use public folders to: Post information on an electronic bulletin board.

What is the difference between a public folder and a shared folder? ›

Both shared mailboxes and public folders can store Outlook type items such messages and calendar events. Both can receive emails (if public folders are mail enabled). However, public folders are considered as a companywide collaboration tool which can be accessed by anyone in your organization.

How do I give access to public folders in Office 365? ›

Set or change permissions for a public folder
  1. In the Folder Pane, right-click the public folder to set permissions, and then click Properties. ...
  2. On the Permissions tab, under Permissions, choose a permissions level from the list.

What is the difference between a public and private group in Office 365? ›

Public Groups: Searchable and other users can join without approval from Team owner. Private Groups: Not searchable, and Team owner must add members for users to join.

Do public folders have email addresses? ›

Mail-Enabled Public Folders allow the folder to receive email directly to it. They are assigned an SMTP address once you set the folder to be mail-enabled.

What replaces public folders? ›

Should you migrate your public folders to Microsoft 365 Groups? Microsoft 365 Groups is the latest collaboration offering from Microsoft, which means there are many reasons why they would be a preferable solution over public folders, a much older technology.

Should I use public folders? ›

Public folders are a great place to store email that multiple people within an organization need to access. For example, an accounting department can use public folders to let department members use Outlook to access the accounting public folders and corresponding email content.

What are the limitations of Office 365? ›

Disadvantages of Office 365
  • Subscriptions aren't for everyone. You don't have to pay out one-time costs, but you do have to pay every month. ...
  • Compatibility issues with bespoke systems. ...
  • Constant updates mean constant changes. ...
  • Most people only use 20% of the functionality. ...
  • You don't actually own the software.

What are the 5 different file and folder permissions? ›

There are six standard permission types which apply to files and folders in Windows: Full Control. Modify. Read & Execute.
...
Write
  • create folders.
  • add new files.
  • delete files.
Sep 9, 2022

What is the use of public folder in Outlook? ›

Public folders in Outlook give you a great place to collect, organize, and share information about particular topics or projects within an organization. "Public" in this case means viewable by everyone within the organization, not the world at large.

How do I use a public folder? ›

How to enable Public folder
  1. Open Control Panel.
  2. Click on Network and Internet.
  3. Click on Network and Share Center.
  4. On the left pane, click on Change advanced share settings.
  5. Expand All Networks.
  6. Make sure to select the Turn on sharing so anyone with network access can read and write files in the Public folders option.
Sep 19, 2017

What are the three types of folders? ›

Overview
  • Quick File Folder. Tap the [Quick File] key to save the scanned data in this folder. A user name and file name are automatically assigned to each job.
  • Main Folder. Tap the [File] key to save the scanned data in this folder. ...
  • Custom Folder. You can name a folder and store it in the custom folder.

Why do I have a public folder under users? ›

The Public folder is a folder in the Windows operating system that you can use to share files with other people who either use the same computer or are connected to the computer over the same network. It's possible to grant or restrict access to your Public folder for any device on a shared network.

Should I delete public user folder? ›

The Public folders are part of the operating system and should not be deleted. They have legitimate uses. Their presence is not harming your computer.

Can I delete the Public folder in users? ›

You can't delete a mail-enabled public folder.

Can you view public folders in OWA? ›

When using web version of Outlook 365 (previously known as OWA), public folders are not immediately available by default. You will need to add the public folders in to your Favorites (a set of folders within your mailbox) before you can view them from your Office 365 mailbox.

Why can't I see public folders in Outlook? ›

To see other types of public or shared folders, open the appropriate view in Outlook, i.e. click on Calendars or Contacts in the shortcut bar. Alternatively, select Go | Folder List from the Outlook menu and you will be able to see all public and shared folders that you have access to.

Is it better to make a group private or public? ›

Public groups can't be hidden, and they're a good option if you want to prioritize quantity in terms of group members. If you want to scale fast and it doesn't really matter who joins, this option can work. In most cases, however, private Facebook groups are going to be the best bet for businesses.

Should I make my group Public or private? ›

Key Tips. Make your group public if you want it to be easily found and if you want posts in the group to be visible to non-members. Choose the private but visible in search setting if you want people to be able to search for and easily discover your group, but keep posts visible to members only.

What is a public group in Office 365? ›

Public Office 365 Group

Public Group means everyone can join it freely without obtaining permissions from the Group Owner. In other words – free lunch for all. Any member can join and have Add/Edit/Delete access to all the assets of an Office 365 Group (SharePoint Site, Planner, Calendar, Teams).

How many public folder mailboxes can you have? ›

Although you can create more than 1,000,000 public folders, it is not officially supported. For any deployment of 100,000 or more public folders, we recommend reading Considerations when deploying public folders. Although you can create more than 1,000 sub-folders under a parent folder, it is not recommended.

What is the difference between a mailbox and a folder? ›

A mailbox is essentially a folder. Some, like inbox or drafts, are pre-built; others are created by the user. The best these can do is have messages filtered into them by simple rules, usually set up on the server side for IMAP accounts.

How do I assign an email address to a public folder? ›

Go to EAC > Public Folders > Public Folders. Select the Public Folder you created, check whether it is mail-enabled (If it is mail-enable, then only you can see the additional settings and email address is assigned). Click Edit. Address you can see for Public Folder (Twitter) is [email protected].

How do I move files to public folder? ›

Make a file available to all users of your Mac

Put a file in your Public folder: Click the desktop to make sure you're in the Finder, choose Go > Home, then drag the file (or a copy of it) into your Public folder.

Where are public folders in new Outlook? ›

Accessing Public Folders in Outlook 2016 or 2019

You will now see a new section in the navigation bar on the left side of the screen called Public Folders - your email address. Click on the arrow to expand the section and then select All Public Folders. The public folders are listed in alphabetical order by department.

How do I recover a deleted public folder? ›

To recover deleted subfolders:
  1. Open Outlook > Folder view > Public Folders and select the Public Folder that contains the deleted subfolder.
  2. Right-click on the selected Public Folder > Recover deleted items > select data for restore > mark Restore Selected Items > Ok.
May 6, 2022

Where are Exchange public folders stored? ›

Public Folders are stored in a separate mailbox called Public Folder Mailbox. To create Public Folders, administrators must create at least one Public Folder mailbox via Exchange Management Shell (EMS) or Exchange Admin Center (EAC).

What are two advantages of Office 365? ›

The top 8 Office 365 benefits
  • Over 150% ROI. ...
  • Have all the tools your business needs to work more efficiently. ...
  • Access your office anywhere, anytime. ...
  • Easily scalable. ...
  • Cross-collaboration has never been easier. ...
  • Stay updated. ...
  • You'll always be secure in Office 365. ...
  • Have the flexibility to mix and match.

What 2 things can Office 365 be used for? ›

Office 365 lets you share mailboxes, calendars, contacts and edit documents in real time through collaborative tools. Sharing calendars in Exchange means you can see who in your organisation is available when, so you can schedule meetings that work for everyone, first time round.

Where are Microsoft 365 files stored? ›

There are three places where you can store, edit, and share files: OneDrive (personal), OneDrive for Business, and Microsoft 365 team sites.

What are four basic permissions? ›

There are four categories (system, owner, group, and world) and four types of access permissions (Read, Write, Execute and Delete).

What are two key types of access permissions? ›

Rule-based and role-based are two types of access control models. The two systems differ in how access is assigned to specific people in your building. Note: Both rule-based and role-based access control are represented with the acronym “RBAC.” For simplicity, we will only discuss RBAC systems using their full names.

What does 777 mean in file permission? ›

you can read and write; others can only read. 777. anyone can do anything (read, write, or execute) 755. you can do anything; others can only read and execute.

Do file permissions override folder permissions? ›

Also true: File permissions override folder permissions, unless the Full Control permission has been granted to the folder.

What are the six NTFS file permissions? ›

The Write NTFS permission is actually made up of the Create Files/Write Data, Create Folders/Append Data, Write Attributes, Write Extended Attributes, Read Permissions, and Synchronize special access permissions.

What is public folder in Exchange Online? ›

Public folders are designed for shared access and provide an easy and effective way to collect, organize, and share information with other people in your workgroup or organization. Public folders help make content in a deep hierarchy easier to browse.

How do I know if my public folder is mail enabled? ›

Navigate to Public folders > Public folders. In the list view, select the public folder that you want to mail-enable or mail-disable. In the details pane, under Mail settings, click Enable or Disable.

How do public folders work? ›

Techopedia Explains Public Folder

A public folder is a quick and easy way to share files and information; the user simply has to move or copy a file into a public folder and it instantly becomes viewable by other users and devices with the proper settings and restrictions set by default by the application.

What is public folder in Salesforce? ›

The Unfiled Public Reports Folder contains shared custom reports created by your Administrator, but not filed into a Custom Report Folder. This folder is generally used as a placeholder folder for new reports until a Custom Report Folder has been created.

How do I use public folder mailbox in Office 365? ›

Instructions
  1. Launch the Office 365 Admin Portal.
  2. Click Admin centers > Exchange in the navigation panel to be taken to the Exchange Admin Center. (See figure below.)
  3. Click public folders in the navigation panel.
  4. Click the + to create a new Public Folder. (See figure below.) ...
  5. Name the new Public Folder.
  6. Click SAVE.
Jul 29, 2019

Where are public folders in Outlook 365? ›

Within Outlook, go to the Folders section by clicking the ellipsis at the bottom of the window and choosing Folders. Expand the Public Folders – login@bu.edu folder in the left hand column, where login is your BU username.

What can I use instead of public folders? ›

Use Office 365 / SharePoint Online to replace Public Folders

Saving to the SharePoint Online areas used by Teams sites is no better. Users complain that: It is more difficult to visualise the structure of the new SharePoint based email store.

How do I clean up my public folder? ›

Navigate to Public folders > Public folders. In the list view, select the public folder you want to delete. Note that clicking on the folder name will display sub-folders within that folder, if there are any. At that point you can click to select a specific sub-folder to remove.

Where are public folders stored? ›

Public Folders are stored in a separate mailbox called Public Folder Mailbox. To create Public Folders, administrators must create at least one Public Folder mailbox via Exchange Management Shell (EMS) or Exchange Admin Center (EAC). There are two types of Public Folder mailboxes.

Is Public folder sharing on or off? ›

Public folder is enabled by default for local users, and you can't turn it off, as it's just a folder Windows creates with special settings on every installation. However, you have to manually enable Public folder, if you want network users to access your shared files.

Videos

1. OO20 - Public Folders & Mail Boxes in Office 365
(Trial & Error - Self Paced Learning)
2. Microsoft 365 Tutorial How to create a Public Folder Mailbox
(Robert McMillen)
3. Microsoft 365 Tutorial How to mail enable a Public Folder
(Robert McMillen)
4. How to migrate Exchange public folders to a shared mailbox in Office 365
(iLikeIT.info)
5. Learn how to Take the risk out of Public Folder Migration to Office 365 (Exchange Online)
(Priasoft)
6. Microsoft 365 Tutorial How to create a Public Folder
(Robert McMillen)
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