Move contacts out of a public folder so they reach every phone

Contacts in a public folder can only be seen in Outlook on the desktop. Outlook for iPhone and Android cannot open public folders, and Microsoft is retiring Exchange Web Services (EWS) in Exchange Online, which tools use to read the folder’s contacts. This guide moves the contacts to a contact folder in a shared mailbox, which ModernSync uses as its source.

The problem: EWS is closing, and public folders aren’t moving to Graph

• Microsoft starts turning off EWS in Exchange Online on 1 October 2026 and retires it completely on 1 April 2027.
• Microsoft Graph, which replaces EWS, will not get operations to read and write items in public folders. Microsoft lists this among the EWS capabilities that won’t be added to Graph.
• Outlook for iOS and Android cannot connect to public folders.

If a tool currently copies contacts from a public folder to phones through EWS, it stops working once EWS is turned off for your organisation. Ask the vendor how the tool will read the folder after April 2027.

What to do instead: a contact folder in a shared mailbox

A shared mailbox is an ordinary mailbox in Exchange Online that several people can work in. It needs no licence. ModernSync reads the contact folder in the shared mailbox and puts the contacts into every employee’s own contacts each night. The phone syncs them like any other contacts.

You need: a Global Administrator or Exchange Administrator in Microsoft 365 and a PC with classic Outlook for Windows. Only those two admin roles can choose a mailbox as a source in ModernSync.

1. Create a shared mailbox

1. Open the Microsoft 365 admin center and go to Teams & groups → Shared mailboxes.
2. Select Add a shared mailbox and give it a name, such as Contacts (contacts@yourcompany.com).
3. After the mailbox is created, select the link Add members to your shared mailbox, choose Add members, select the person who will move the contacts, and choose Add. Members get full access. After Saved. the list may still say that no members have been added for a few minutes. That is normal. The mailbox appears in classic Outlook by itself after a while (up to an hour).
4. Start using the mailbox and wait about 15 minutes before you create any folders. A new shared mailbox has no default Contacts folder until it has been used. Classic Outlook still shows one and creates a folder called Contacts. If you create a folder there, it lands at the root of the mailbox rather than under Contacts, and ModernSync cannot find it. Set the language on the mailbox first. Two ways:
   • An administrator runs this in Exchange Online PowerShell: Set-MailboxRegionalConfiguration -Identity <shared mailbox> -Language en-GB -LocalizeDefaultFolderName, using the language your organisation works in. We tested the command, with Danish settings, in our demo tenant. With English the folder is called Contacts.
   • Open the mailbox once in Outlook on the web and choose your language. This may also work, but we have not tested it.

2. Create a contact folder in the shared mailbox

1. Open classic Outlook and go to Contacts.
2. Find the shared mailbox in the folder list. In the contacts view it appears as Contacts - . Right-click it and select New Folder. Give it the same name as the public folder, such as Suppliers.

You can also put the contacts straight into the shared mailbox’s Contacts folder. Use a new folder if you have several public folders that should stay separate.

3. Copy the contacts

Outlook cannot copy straight from a public folder to a shared mailbox when it downloads shared folders locally (the default). It gives the error The changes to the item were lost because the connection to the server was restored, and the folder stays empty. Copy to a folder in your own mailbox first, and on from there.

1. Go to the Folders view. Right-click Contacts in your own mailbox, choose New Folder, and name it, for example, Suppliers (temporary).
2. Expand Public Folders → All Public Folders and open the contact folder. Select all contacts with Ctrl+A.
3. Right-click and choose Move → Copy to Folder. Pick the temporary folder from step 1.
4. Open the temporary folder and select all contacts with Ctrl+A. Choose Move → Other Folder… and pick the folder in the shared mailbox from section 2.
5. Compare the number of contacts in the public folder and in the folder in the shared mailbox. Outlook shows it at the bottom of the window. If there are fewer, copy again.
6. Once the numbers match, you can delete the temporary folder in your own mailbox.

The public folder stays as it is until you have seen the contacts on the phones.

Phones get the ordinary contacts. Contact groups (such as Tradesmen) do not come along, only contacts. The groups stay in Outlook.

4. Create the rule in ModernSync

1. Sign in to the portal and go to Rules → Add rule.
2. Choose A contact folder in a mailbox.
3. Enter the shared mailbox’s address under Mailbox, such as contacts@yourcompany.com, and the folder name under Folder. Leave Folder empty if the contacts are in the shared mailbox’s Contacts folder. This requires that you followed step 1: otherwise the folder is not the default Contacts folder and ModernSync cannot find it.
4. Choose the group that should get the contacts and save the rule.
5. Start a Test run. It shows how many contacts each employee will get and writes nothing.

Once you turn runs on, the rule runs every night. New and changed contacts in the shared mailbox, such as a corrected mobile number, go out at the next run and show on the phone after a few minutes.

5. Once the contacts are on the phones

• Ask colleagues to maintain the contacts in the shared mailbox from now on.
• Make the public folder read-only or remove it, so there is only one place to make changes.

If something doesn’t work

Problem	Fix
The shared mailbox doesn’t show up in Outlook	Wait up to an hour or restart Outlook. Check that the person is a member of the shared mailbox
Public Folders is missing in the Folders view	New Outlook does not show public folders. Switch to classic Outlook
The copy gives an error and the folder is empty	Use the route via your own mailbox in section 3. Or turn off Download shared folders: File → Account Settings → Account Settings → your account → More Settings → Advanced. Restart Outlook, copy directly, and turn it back on
The test run finds no contacts	Check the spelling of the folder name and the mailbox address. If the folder sits at the root of the mailbox instead of under Contacts, create it again after step 1

Sources

Microsoft Learn, read on 18 October 2026:

• Deprecation of Exchange Web Services in Exchange Online: the timeline and the list of capabilities that won’t be added to Microsoft Graph.
• Exchange Online service description: the dates 1 October 2026 and 1 April 2027.
• FAQ about public folder migration: Outlook for iOS and Android and public folders.