Ways to increase email size limit in Exchange Server 2013

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Effective mail flow within Exchange Server is essential for maintaining a competent database system. The accumulation of large attachments in emails causes unnecessary storage consumption. Fortunately, there are solutions available to address this concern. By configuring email size limits through the Exchange Management Shell and Exchange Admin Center, administrators can efficiently control the volume of data.

Moving further in this blog, we will discuss different ways to change email size limit in Exchange Server for a single mailbox as well as for the complete server. Additionally, we will also discuss how to recover data from a corrupted oversized EDB file using a professional Exchange database recovery tool.

Types of message size limits in Exchange

Here are a few categories that define the message size limits you can modify in an Exchange Server:

• Message header limit: The email message header contains information about the email route, sender, recipient, and whether the message is spam or found with viruses.
• Message size limit: You can define the limit on incoming and outgoing email messages. The limit includes the total message size, including header, body, and attachment.
• Attachment size limit: Defines the size of individual attachments only. A message can have more than one attachment, affecting the overall size of a message.
• Recipient limit: Allows limiting the number of recipients you can send messages to and are mentioned in To, Cc, and Bcc of an email.

If you increase the email size limit in Exchange Server, you will start receiving larger emails. Gradually, this will lead to an oversized EDB file, and you will start experiencing issues like lag, email send/receive errors, and more. To avoid these, I suggest auditing the database every few months and archiving the old mailboxes or extracting them to a local hard disk using tools like EDB to PST Converter.

Why increase email size limit in Exchange Server?

Mostly, admins choose to change the size limit when they get the following errors:

• “552: Message size exceeds maximum permitted.”
• “System Undeliverable, message size exceeds outgoing message size limit.”
• “Attachment size exceeds the allowable limit.”
• “The size of the message you are trying to send exceeds the global size limit of the server. The message was not sent; reduce the message size and try again.”

Considerations for setting message size limits

Before you adjust the email size limit in Exchange Server, here are some things that you need to consider:

• Maximum size limits on incoming and outgoing messages.
• Mailbox storage quota and maximum message size limits.
• Users who are allowed to use more than current specified message size limits for sending/receiving emails.

Keeping these considerations in mind, let us understand how we can alter the default mail size limits in Exchange Server 2013.

How to increase email size limit in Exchange Server?

You can easily change email size limit in Exchange Server 2013 using Exchange Management Shell or Exchange Admin Center. Let’s follow the process to alter the limits:

Use Exchange Management Shell to increase email size limit in Exchange Server

First, open Exchange Management Shell on your Exchange Server. Check the current server limit on emails by running the following cmdlets.

To check the Transport service email limits, run this command:

To check receive/send connector service email limits, run the following command:

Note: Use “send” in place of “receive” in cmdlet to check send connector service email limit.

Now, to change the email size received by the Transport service, execute the following cmdlet:

Note: You can either increase or decrease the message size limit using the above cmdlet.

Also, you can set limits for the results of the get-transportconfig cmdlets as:

Note: The above cmdlets do not consider whether the attachments are included or not. Large messages with no attachments might stop immediately.

To set a Transport rule to avoid receiving attachments above a certain size limit (here 10MB) and to display a message, run the following cmdlet:

Thus, you can make use of Exchange Management Shell to manage the email size limit of your Exchange Server. Let us have an easier way to set these limits through the Exchange Admin Center.

Use Exchange Admin Center to change email size limit in Exchange Server

Exchange Admin Center allows setting the email size limit flowing into the server. To do this, perform the following steps one-by-one:

1. Navigate to Exchange Admin Center>mail flow>receive connectors>… (more) and click Organization transport settings.
2. In Organization transport settings, edit the values of Maximum number of recipients, Maximum receive message size (MB), and Maximum send message size (MB). Finally, click Save.

How to change email size limit in Exchange Server for an individual mailbox?

To change the size limit of email for a single mailbox in your organization using the EAC, follow these steps:

• In the EAC, go to Recipients > Mailboxes.
• You will see the list of all the mailboxes currently in your organization.
• Select the mailbox whose limits you want to change and click the Edit icon (pencil button).
• From the left-side navigation pane, select mailbox features option.

On the right-side pane, under the Message Size Restriction, click View Details, and set the limits as per the requirements.

Note: Do not increase email size limit in Exchange Server for incoming and outgoing messages to more than 150MB.

To change email size limit for a single mailbox using the EMS, use this cmdlet:

Set-Mailbox “user-mailbox” -MaxSendSize “size-in-mb” -MaxReceiveSize “size-in-mb”

How does managing email size limit helps to prevent corruption?

By default, when a new mailbox is created, it is not bound by any size limit rules; instead, the rules governing the whole organization’s email traffic are applied to it. Exchange has introduced these rules to protect the database from different issues. One of the major benefits of setting up size rules in Exchange is that it helps the admin protect their database from corruption.

When you continuously get large emails, sooner or later your EDB file will cross the size threshold limit. When that happens, you will face constant database dismounting and crashing issues. Multiple occurrences of such Exchange issues often lead to corruption of database pages.

How to repair a corrupt Exchange database file?

In the event of Exchange database corruption, your EDB file will be dismounted from the server. To fix it, immediately use the eseutil tool. However, the native tool comes with the risk of data loss. A better and recommended approach is to use a professional Exchange database recovery tool.

The Kernel for Exchange Server is a complete solution that helps fix different issues related to Exchange Server, including EDB corruption. This tool supports dismounted or orphaned EDB files suffering from minor or severe corruption. You can add and repair EDB files of massive size, and after recovery, save the data to an offline PST file, a live Exchange Server, or an Office 365 account.

Summing Up

Organizations with a large number of mailboxes must carefully change email size limit in Exchange Server. You cannot set it too low or too high, as both are risky. Most admins recommend choosing a size limit between 35 MB and 100 MB. After deciding what limits are best for you, use either the Exchange Management Shell or the Exchange Admin Center to manage the limits.

However, in case an oversized EDB file or other issues corrupt your database, do not take the risk with manual recovery methods. Repair corrupt EDB files without losing emails with the professional Exchange recovery tool.

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