Change Exchange 2010 incoming/outgoing message size limit

Default incoming/outgoing message size limit in an Exchange environment is typically 10MB. If you need to send or receive larger attachments, you will run into problems. As today for example gmail.com allows 25MB attachments, you probably want to allow those e-mails to reach your users.

The limit is present in Exchange configuration in several places:

1. Organizational limit
2. Receive Connector limits
3. Send Connector limits

There are a lot of more places to look at, if those don’t work. In this case look first http://technet.microsoft.com/en-us/library/bb124345.aspx for more information.

To get current configuration quickly, you can use following commands on Exchange Management Shell:

Get-TransportConfig | ft MaxReceiveSize,MaxSendSize -a
Get-ReceiveConnector | ft Name,MaxMessageSize -a
Get-SendConnector | ft Name,MaxMessageSize -a

To change the sizes to one particular number (25MB for example):

$m=25MB
Get-TransportConfig | Set-TransportConfig –MaxReceiveSize $m
Get-TransportConfig | Set-TransportConfig –MaxSendSize $m
Get-ReceiveConnector | Set-ReceiveConnector –MaxMessageSize $m
Get-SendConnector | Set-SendConnector -MaxMessageSize $m

Afterwards you should check the results with the first 3 commands:

And you should be able to send and receive e-mails with larger attachments now. Of course, if you have 3rd party systems on the path of your e-mail, you must change those also.