6. Mail-enabling public folders
By
default, public folders are not mail-enabled; users cannot add content
by including a public folder as an addressee for a message. In fact,
one of the most common uses for public folders is as a repository to
capture the messages sent to distribution groups that would otherwise
be unavailable to people who are not part of the group or who join the
group after a discussion has occurred.
Mail-enabling a public
folder is easy. Select the folder in EAC and then click the Enable link
under Mail Settings in the details pane (Figure 8).
EAC prompts you to confirm the action. If confirmed, Exchange populates
a set of mail-related properties for the public folder so that the
folder can participate in message transport.
The
Get-PublicFolder command does not reveal all the properties for a
mail-enabled public folder. Instead, use the Get-MailPublicFolder
command to retrieve the properties and Set-MailPublicFolder to update
the properties. To show the kinds of properties that are populated when
a public folder is mail-enabled, here’s an edited version of the output
from Get-MailPublicFolder. Apart from the ContentMailbox property
(pointing to the public folder mailbox that contains the content for
the folder), these properties look very similar to what you’d see for a
user mailbox:
ContentMailbox : contoso.com/Exchange users/PF-IT-MBX
AcceptMessagesOnlyFrom : {}
AcceptMessagesOnlyFromDLMembers : {}
AcceptMessagesOnlyFromSendersOrMembers : {}
AddressListMembership : {\MailPublicFolders(VLV), \All Recipients(VLV), \Default Global Address List,\Public Folders}
Alias : Mobiledevices
OrganizationalUnit : contoso.com/Microsoft Exchange System Objects
EmailAddresses : {SMTP:[email protected]}
GrantSendOnBehalfTo : {}
HiddenFromAddressListsEnabled : False
LegacyExchangeDN : /CN=Mail Public Folder/CN=Version_1_0/CN=e66f783b-adf3-48a7-bed3-bb74f5c79be2/CN=xxxx
MaxSendSize : Unlimited
MaxReceiveSize : Unlimited
In
addition, mail-enabled public folders are represented as Active
Directory objects in the Microsoft Exchange System Objects
organizational unit (OU), as shown in Figure 9.
This allows the public folders to be found when Active Directory is
consulted to know how best to route a message for delivery.
Read
through the properties listed previously and note that public folders
are included in some address lists and are exposed to users when they
browse the GAL. In Figure 10,
you can see the entries for two mail-enabled public folders. Users can
send messages to the public folders by including them in the set of
addresses. However, there’s no real need to reveal the presence of
mail-enabled public folders in the GAL unless you really want to. The
normal approach is to include the mail-enabled public folder as a
recipient in the distribution group for which it will serve as a
repository and then hide the public folder from address lists. A
command similar to the one shown here will do the job:
Set-MailPublicFolder –Identity "\Departments\IT\Exchange 2013" –HideFromAddressListsEnabled $True
Alternatively,
select the folder with EAC and click the pencil icon to reveal all the
properties with which you’d normally expect to work for a user mailbox.
Figure 11
shows that this folder is a member of a distribution group, so a copy
of every message posted to the members of the group will be delivered
to and available in the public folder.
The
Delivery Options section of a mail-enabled public folder’s properties
permits an administrator to enable other users to Send On Behalf Of the
folder or Send As the folder. In the past, public folders were often
used as the source of service-type messages such as those generated to
inform a user when something was done on his behalf (for example,
granting him a larger mailbox quota). Shared mailboxes are more popular
now, but the facility still exists to use a public folder for this
purpose.
