You use mailbox properties to set delivery restrictions,
permissions, and storage limits. To change these configuration settings
for mailboxes, follow the techniques discussed in this section.
Setting message size restrictions for contacts
You
set message size restrictions for contacts in much the same way that
you set size restrictions for users. Follow the steps listed in the
next section.
Setting message size restrictions on delivery to and from individual mailboxes
Message size restrictions control the maximum size of messages that
can be sent or received in the Exchange organization. With Exchange
Online, the maximum size of messages that users can send is 35,840 KB
and the maximum size of messages that users can receive is 36,864 KB by
default. With on-premises Exchange, you can manage these settings in a
variety of ways. Typically, you manage these restrictions for the
organization as a whole using the Organization Transport Settings. To
manage these settings complete these steps:
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In Exchange Admin Center, select Mail Flow in the feature pane and then select Receive Connectors.
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On the Receive Connectors page, tap or click More Options and then select Organization Transport Settings.
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By default the maximum receive and send message size are both set to
10 MB. Use the options on the Limits page to set new defaults and then
tap or click Save.
You also can manage these restrictions using transport rules that
filter messages by size and have specific conditions that apply to the
size of messages or attachments, including the Apply This Rule If The
Message Size Is Greater Than Or Equal To condition and the Apply This
Rule If Any Attachment Is Greater Than Or Equal To condition.
Using the Apply This Rule If The Message Size Is Greater Than Or Equal To condition, you can:
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Set restrictions regarding the size of messages that can be sent or received.
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Specify the action or actions to take if a message meets or exceeds this limit.
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Define exceptions for specific users and groups as well as for messages that have specifically-defined characteristics.
In Exchange Admin Center, you can create and manage transport rules,
using the options found under Mail Flow > Rules. Tap or click New
and then select Filter Messages By Size. The shell commands for working
with transport rules include: Disable-TransportRule,
Enable-TransportRule, Get-TransportRule, New-TransportRule,
Remove-TransportRule, and Set-TransportRule.
When setting these types of organization-wide restrictions, you’ll
want to consider the global impact. Typically, you’ll want to apply
organization-wide restrictions only to prevent abuse of the mail
system. For example, you may want to configure rules that block sending
and receiving of very large files and provide a message that encourages
senders to use a site mailbox configured as part of a Microsoft
SharePoint site for sharing large documents instead.
Sometimes, you need to
set exceptions for specific users. For example, some users might need
to be able to send large files as part of their job.
For online Exchange, delivery restrictions are fixed for individual
users. For sending messages, the maximum message size is 35,840 KB. For
received messages, the maximum message size is 36,864 KB.
For on-premises Exchange, you set individual delivery restrictions 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 Features page, scroll down and then tap or click View Details under Message Size Restrictions.
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As shown in Figure 1, you can set the following send and receive restrictions:
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Sent Messages > Maximum Message Size
. Sets a limit on the size of messages the user can
send. The value is set in kilobytes (KBs). If an outgoing message
exceeds the limit, the message isn’t sent and the user receives a
non-delivery report (NDR).
-
Received Messages > Maximum Message Size
. Sets a limit on the size of messages the user can
receive. The value is set in KBs. If an incoming message exceeds the
limit, the message isn’t delivered and the sender receives an NDR.
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Tap or click OK and then tap or click Save. The restrictions that you set override the global default settings.
Setting send and receive restrictions for contacts
You set message send and receive restrictions for contacts in the
same way that you set these restrictions for users. Follow the steps
listed in the next section.
