Setting storage restrictions on mailbox and archives
In a standard configuration of Exchange Online, each licensed user
gets 25 GB of mailbox storage, and a storage warning is issued when the
mailbox reaches 22.5 GB. Similarly, if a user has a licensed in-place
archive, the archive can have up to 25 GB of storage; a storage warning
is issued when the archive mailbox reaches 22.5 GB. Other licensing
options are available that may grant additional storage rights.
With on-premises
Exchange, you can set storage restrictions on multiple mailboxes using
global settings for each mailbox database or on individual mailboxes
using per-user restrictions. Global restrictions are applied when you
create a mailbox and are reapplied when you define new global storage
restrictions. Per-user storage restrictions are set individually for
each mailbox and override the global default settings. By default,
users can store up to 2 GB in their mailboxes. The quotas are set to:
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Issue a warning when the mailbox reaches 1.9 GB
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Prohibit send when the mailbox reaches 2 GB
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Prohibit send and receive when the mailbox reaches 2.3 GB
In contrast, the default settings for archive mailboxes allow users
to store up to 50 GB in their archive mailboxes, and a warning is
issued when the archive mailbox reaches 45 GB.
Note
Storage restrictions apply only to mailboxes stored on the server.
They don’t apply to personal folders. Personal folders are stored on
the user’s computer.
To configure global storage restrictions, you edit the properties of
mailbox databases. In Exchange Admin Center, navigate to Servers >
Databases. Open the Properties dialog box for the mailbox database by
double-tapping or double-clicking the database name. On the Limits
page, set the desired storage restrictions using the options provided.
Set individual storage restrictions for mailboxes by completing the following steps:
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Open the Properties dialog box for the mailbox-enabled user account
by double-tapping or double-clicking the user name in Exchange Admin
Center.
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On the Mailbox Usage page, tap or click More Options. You’ll then see the storage restrictions as shown in Figure 3.
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To
set mailbox storage limits, select Customize The Quota Settings For
This Mailbox. Then set one or more of the following storage limits:
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Issue Warning At (GB)
. This limit specifies the size, in gigabytes, that a
mailbox can reach before a warning is issued to the user. The warning
tells the user to clean out the mailbox.
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Prohibit Send At (GB)
. This limit specifies the size, in gigabytes, that a
mailbox can reach before the user is prohibited from sending any new
mail. The restriction ends when the user clears out the mailbox and the
mailbox size is under the limit.
-
Prohibit Send And Receive At (GB)
. This limit specifies the size, in gigabytes, that a
mailbox can reach before the user is prohibited from sending and
receiving mail. The restriction ends when the user clears out the
mailbox and the mailbox size is under the limit.
Caution
Prohibiting send and receive might cause the user to think they’ve
lost email. When someone sends a message to a user who is prohibited
from receiving messages, an NDR is generated and delivered to the
sender. The original recipient never sees the email. Because of this,
you should rarely prohibit send and receive.
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Tap or click Save.
Users who have an archive mailbox have the mailbox type User
(Archive). You set individual storage restrictions for archive
mailboxes by completing the following steps:
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Select the user name in Exchange Admin Center.
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In the detail pane, scroll down until you see the In-Place Archive heading and the related options. Tap or click View Details.
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Enter the desired maximum size for the archive in the Archive Quota text box.
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Enter the storage limit for issuing a storage warning in the Issue Warning At text box, and then tap or click OK.
Setting deleted item retention time on individual mailboxes
Normally, when a user deletes a message in Outlook, the message is
placed in the Deleted Items folder. The message remains in the Deleted
Items folder until the user deletes it manually or allows Outlook to
clear out the Deleted Items folder. With personal folders, the message
is then permanently deleted and can’t be restored. With server-based
mailboxes, the message isn’t actually deleted from the Exchange
database. Instead, the message is marked as hidden and kept for a
specified period of time called the deleted item retention period.
Note
The standard processes can be modified in several different ways. A
user could press Shift+Delete to bypass Deleted Items. As an
administrator, you can create and apply policies that prevent users
from deleting items (even if they try to use Shift+Delete). You can
also configure policy to retain items indefinitely.
Default retention settings are configured for each mailbox database
in the organization. With Exchange Online, the retention settings are
as follows:
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Deleted items are retained for a maximum of 30 days.
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Items removed from the Deleted Items folder are retained for a maximum of 14 days.
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Items in the Junk Folder are retained for a maximum of 30 days before they are removed.
To configure deleted item retention on a per database basis, you
edit the properties of mailbox databases. In Exchange Admin Center,
navigate to Servers > Databases. Open the Properties dialog box for
the mailbox database by double-tapping or double-clicking the database
name. On the Limits page, use the options provided to configure the
deleted item retention settings.
To override the database settings on a per-user basis, complete these steps:
-
Open the Properties dialog box for the mailbox-enabled user account
by double-tapping or double-clicking the user name in Exchange Admin
Center.
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On the Mailbox Usage page, tap or click More Options and then select Customize The Retention Settings For This Mailbox.
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In the Keep Deleted Items For (Days) text box, enter the number of
days to retain deleted items. An average retention period is 14 days.
If you set the retention period to 0 and aren’t using policies that
prevent deletion, messages aren’t retained and can’t be recovered. If
you set the retention period to 0 but are using policies that prevent
deletion, the messages are retained according to the established
policies.
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You can also specify that deleted messages should not be permanently
removed until the mailbox database has been backed up. This option
ensures that the deleted items are archived into at least one backup
set. Tap or click Save.
Real World
Deleted item retention is convenient because it allows the
administrator the chance to salvage accidentally deleted email without
restoring a user’s mailbox from backup. I strongly recommend that you
enable this setting, either in the mailbox database or for individual
mailboxes, and configure the retention period accordingly.
