Resolve the issue “Exchange 2010 not sending large attachments.”

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Has it happened with you that while trying to send an email with a big attached file via Exchange 2010 and faced the error mentioning that “attachment size exceeds the allowable limit”? If yes, then you might have got some idea by now about the messaging limits in Exchange Server.

Due to these message limits, Exchange users face issues while sending/receiving large emails or emails with large attachments.

So, there is a need to change the limits set on message or attachment. You have two methods for modifying the set message size limits – using Exchange Management Console and Exchange PowerShell.

We will discuss here the methods to change max email size in Exchange 2010.

Modify message size limits using Exchange Management Console

Exchange 2010 administrators can increase the message size limit using the Exchange Management Console.

Note: By default, the maximum message size is 10MB for both incoming and outgoing messages in Exchange 2010.

For this, open the Exchange Management Console. Then, expand the Organization Configuration and then Hub Transport. Go to Global Settings tab and after that to Transport Settings; open its Properties. A new window with Transport Settings Properties will get open. On the General tab, you can easily modify the Maximum receive size and Maximum send size for emails in KB (which is by default set at 10MB). It can be increased up to 2GB of size.

Now, you can change the maximum message size limits for Send and Receive Connectors in the same manner. For that, follow these paths in the Exchange Management Console:

• For Send Connectors: Go to Organization Configuration >> Hub Transport >> Send Connectors ‘send connector’ Properties
• For Receive Connectors: Go to Server Configuration >> Hub Transport ‘Hub Transport’ >> Receive Connectors ‘Connector’ >> Properties

Here, you can set the Maximum message size as per the requirement.

Modify message size limits using Exchange Management Shell

There is another way to modify the Maximum message size, which is via running cmdlets in the Exchange Management Shell.

To run cmdlets in the Exchange Management Shell, users must have administrative rights. You can create a hub transport rule to set the maximum size of the email attachment and also to send an email rejection message:

You can get the current values for the maximum send/receive messages with the following cmdlets.

A. Get Global Transport Configuration message size limits with this command:

B. To get the Send Connector message size limits, execute this command:

C. To know the current Receive Connector message size limits, use command:

With these commands, you will get the current set message size limits for both send and receive messages.

Now, to modify the present message size limits, use the below-given commands.

Suppose we are changing the message size limits from 10 MB to 50 MB.

A. To modify Transport Configuration message size limits, run the following command:

B. Similarly, for Send and Receive Connectors, use these commands:

The issue of non-delivery of the large attachments could be due to corruption in the Exchange database files as well, and this could be resolved by Kernel for Exchange Server tool. The tool is a smartly programmed to recover EDB data. So, try Exchange Server Recovery software for any kind of EDB file corruption errors.

Conclusion

The reason for the delivery failure of large attachments could be message size limits or corruption issues. With Exchange Management Console or Exchange Management Shell, administrators can set the maximum message size limits. But if there are database corruption issues, they should try a professional Exchange server solution.