Configure message size limits for a mailbox in Exchange Server

Message size limits control the size of messages that a user can send and receive. By default, when a mailbox is created, there isn't a size limit for sent and received messages.

Keep in mind that there are other settings in an Exchange organization that determine the maximum message size a mailbox can send and receive (for example, the maximum message size configured on a Mailbox server). To learn more about the message size restrictions in Exchange, including the types of message size limits, their scope, and the order of precedence, see Message size and recipient limits in Exchange Server.

For additional management tasks related to user mailboxes, see Manage user mailboxes.

Note

You can also control the size of messages sent and received by mail users and from shared mailboxes.

What do you need to know before you begin?

Tip

Having problems? Ask for help in the Exchange forums. Visit the forums at: Exchange Server, Exchange Online, or Exchange Online Protection.

Use the EAC to set message size limits

  1. In the EAC, navigate to Recipients > Mailboxes.

  2. In the list of user mailboxes, click the mailbox that you want to change the message size limits for, and then click Edit Edit icon..

  3. On the mailbox properties page, click Mailbox Features.

  4. Under Message Size Restrictions, click View details to view and change the following message size limits:

    • Sent messages: To set a maximum size for messages sent by this user, select the Maximum message size (KB) check box and type a value in the box. The message size must be between 0 and 2,097,151 KB. If the user sends a message larger than the specified size, the message will be returned to the user with a descriptive error message.

    • Received messages: To set a maximum size for messages received by this user, select the Maximum message size (KB) check box and type a value in the box. The message size must be between 0 and 2,097,151 KB. If the user receives a message larger than the specified size, the message will be returned to the sender with a descriptive error message.

  5. Click OK, and then click Save to save your changes.

Use the Exchange Management Shell to configure message size limits

This example sets the maximum size for sent messages to 25 MB and the maximum size for received messages to 35 MB for the mailbox of Debra Garcia.

Set-Mailbox -Identity "Debra Garcia" -MaxSendSize 25mb -MaxReceiveSize 35mb

For detailed syntax and parameter information, see Set-Mailbox.

How do you know this worked?

To verify that you've successfully set up message size limits for a mailbox, do one of the following:

  1. In the EAC, navigate to Recipients > Mailboxes.

  2. In the list of user mailboxes, click the mailbox that you want to verify the message size limits for, and then click Edit Edit icon..

  3. On the mailbox properties page, click Mailbox Features.

  4. Under Message Size Restrictions, click View details to verify the message size limits for the mailbox.

    Or

    Run the following command in the Exchange Management Shell.

    Get-Mailbox -Identity <Identity> | Format-List MaxSendSize,MaxReceiveSize