How to Change Mailbox Size & Max Email Size in Exchange 2010

Read Time: 5 minutes

Do you get low space alerts or bounced emails in Exchange 2010? The problem is most likely mailbox size or message size limits. Exchange 2010 was one of the most popular versions of Exchange Server. Microsoft ended support for it on 14 January 2020, and later versions (Exchange 2016 and 2019) have also passed end of support, but many organizations still run Exchange 2010 in a legacy environment. By default, Exchange 2010 has a range of limits set to prevent the server from getting overwhelmed, but they often have to be changed as your organization grows. In this blog, we will see how to change mailbox size in Exchange 2010 along with max email size.

About Mailbox Quotas in Exchange 2010

Exchange 2010 mailbox size is controlled by storage quotas, which are set at two levels:

Mailbox Database Level: Applies globally as a baseline rule to all mailboxes hosted inside a specific mailbox database.
Mailbox Level (Per-User Level): Applies to a specific individual mailbox, overriding the database-level default.

These mailbox properties help you track the growing size of a mailbox:

Issue Warning at (MB) – This is the size of the mailbox at which the user will get a warning regarding the size of the mailbox.
Prohibit send at (MB) – This is the size limitation for the mailbox when it stops sending messages from the user’s account.
Prohibit send and receive at (MB) – This is the size limitation for the mailbox when it will stop both sending and receiving the messages from the user’s account.

How to Increase the Size Limit of Mailboxes in Exchange 2010?

Exchange 2010 mailbox database size is controlled by storage quotas. By default, every mailbox inherits the quotas of its mailbox database (1.9 GB warning, 2 GB prohibit send, and 2.3 GB prohibit send and receive). Administrators can override these per mailbox or set them to unlimited. Maintaining limit helps utilize the disk space efficiently. But sometimes, you need to adjust the size of the Exchange 2010 mailbox size so that the user can keep working with their mailbox data.

Option A. Using Exchange Management Console (EMC)

Open Exchange Management Console.
In the left pane, go to Recipient Configuration and then click on Mailbox. All the mailbox(es) present in the Exchange Server will be listed.
Select any mailbox, right-click it, and click Properties.
In the Properties wizard, go to the Mailbox Settings. Select Storage Quotas and click Properties.
Uncheck Use mailbox database defaults, then change any of the:
- Issue warning at (MB)
- Prohibit send at (MB)
- Prohibit send and receive at (MB)
Make changes in the limits and finally click OK.

Option B. Using Exchange Management Shell (PowerShell)

Open Exchange Management Shell and run the below-mentioned command:

Set-Mailbox -Identity “Username” -IssueWarningQuota 2GB -ProhibitSendQuota 2.5GB -ProhibitSendReceiveQuota 3GB -UseDatabaseQuotaDefaults $false

-Identity: The user’s name, alias, email address, or UPN
-UseDatabaseQuotaDefaults $false: Required to stop inheriting the global database size limits.
-IssueWarningQuota: The size threshold at which the user receives a “mailbox almost full” warning email.
-ProhibitSendQuota: The size threshold at which the user can no longer send new emails.
-ProhibitSendReceiveQuota: The maximum hard limit. The user can neither send nor receive incoming emails.c

How to Change Max. Email Size in Exchange 2010?

Sometimes, users face problems when they want to send/receive large emails or attachments because the message exceeds the configured size limit (the default is 10 MB). But administrators can change the email size limitation from the Exchange Management Console. Let’s see it also:

Step 1. Global Transport Settings

After starting the Exchange Management Console, go to the left pane and expand Server Organization Configuration.
Go to Hub Transport, then click Global Settings.
Right-click on Transport Settings and click Properties.
Now you can make changes in the three options –

Maximum receive size (KB)
Maximum send size (KB)
Maximum number of recipients

Click Apply and OK.

Step 2. Receive Connectors & Send Connectors

Receive Connectors (Inbound)

In the Exchange Management Console, go to Server Configuration >Hub Transport.
Select your server, then click on Receive Connectors.
Right-click on the connector and click Properties.
Under General, update the maximum message size (KB) value.

Send Connectors (Outbound)

In the Exchange Management Console, go to Organization Configuration >Hub Transport >Send Connectors.
Right-click on Send Connector and click Properties.
Below General, change the maximum message size (KB).

Step 3. Individual Mailbox Restrictions (Optional)

If a specific user needs a custom override to the global limit:

In the Exchange Management Console, go to Recipient Configuration >Mailbox.
Right-click on the user and select Properties.
Go to Mail Flow Settings >Message Size Restrictions >Properties.
Set the maximum size for sent or received messages.

Read More: Know email limits in Exchange Online for efficient mailbox management.

How to Monitor Mailbox Growth Before Users Hit Their Limits?

When the Exchange mailboxes grow beyond a limit, it may prove fatal for the whole environment. An Exchange administrator must always know the status of each mailbox and there is no manual way to get the status of any mailbox. But you can use any monitoring tool which can analyze the Exchange Server and provide complete details related to mailboxes, mailbox folders, and traffic.

Kernel Exchange Reporter is a proficient analysis and reporting software that generates accurate reports based on all activities on Exchange Server. It is an advanced tool that facilitates the Exchange administrator in gathering valuable information regarding each functional aspect of the emailing system. It collects and consolidates data from multiple sources and stores them in a database. It further generates various statistical reports of Exchange Server mailboxes and presents them in various graphical and tabular formats. This tool works with all the versions Exchange Server like Exchange 2010, 2013, 2016, & 2019.

Final Words

In Exchange 2010, changing mailbox size and max email size is not difficult, but you need to know where to change limits. You can use Exchange Management Console and Exchange Management Shell to increase the size limit of mailboxes as well as emails. However, you should always change limits at the organization level, database level, transport level, or for a specific mailbox.