If you mail-enable a public folder, it happens sometimes, that the folder still isn’t able to receive any mails. If just external mails aren’t received, you may review this thread. If internal mails are also affected the following instructions should do the trick.

If you track those mails on your exchange server, you may receive the following line:

RecipientStatus: {[{LRT=};{LED=550 5.7.1 RESOLVER.RST.NotAuthorized; not authorized [Stage: CreateMessage]};{FQDN=};{IP=}]}

This line says, that the sender was recognized by the exchange infrastructure. And this user has no right to “create items”, because that’s the thing that is basically happening if you send a mail to a public folder. To fix this, we allow all users to “create items” who do not own an explicit right set:

Add-PublicFolderClientPermission -identity "\Folder\Subfolder” –User Default -AccessRights CreateItems

Of course you are able to allow just single users by replacing “Default” with the regarding user. “Default” stands for all those users who were not set up previously.

Often you have to add rights for a new user long after the creation of a public folder. If there’s much Data in this folder and it’s subfolders, the usual method by using the Exchange Control Panel will often result in OutOfMemory-Exceptions. To prevent this behaviour, we could use the Exchange Scripts, which were placed on your server during the installation:

  1. At first we need a new Instance of the Exchange Management Shell (EMS) or a PowerShell Console with loaded Exchange Snapins (can be done by using the command “Add-PSSnapin Microsoft.Exchange.Management.Powershell.Snapin”).This needs to be done as the provided Scripts from Microsoft won’t import those Commands again.
  2. In the Shell we will now change our Working-Directory to the Path, were the Scripts are stored. This can be done by the following command:
    cd “C:\Program Files\Microsoft\Exchange Server\V15\Scripts”
    You may replace the Folder “V15” with the Versionnumber of your Exchange-Server.
  3. Now we will execute the following command:
    .\AddUsersToPFRecursive.ps1 -TopPublicFolder “\[folder-path]” -User “[UPN of the User]” -Permission “[Permission-Set]”
    Bsp.: .\AddUsersToPFRecursive.ps1 -TopPublicFolder “\technet” -User “randomguy@c4y.biz” -Permission “Owner”
  4. After a short delay the console will show you every folder as an output-line to confirm the modification of rights.

That’s it!

Since SP1 for Exchange 2013 it could be possible, that just mail-enabling a Public Folder isn’t enough to make this Folder receiving external Mails. This is caused by a missing permission for external Senders (which appear as “Anonymous”) to “create” items in this specific folder.

If you track an external message, you may receive the following error:

RecipientStatus: {[{LRT=};{LED=550 5.7.1 RESOLVER.RST.AuthRequired; authentication required [Stage: CreateMessage]};{FQDN=};{IP=}]}

To resolve this issue, you have to drop the following command within the Exchange Management Shell:

Add-PublicFolderClientPermission –identity “\Folder\Subfolder” –User Anonymous –AccessRights CreateItems

This should resolve your problem.