How to Resolve Microsoft Exchange 2010 Large Message Restore Errors

Error Message

If you attempt to restore large messages from Microsoft Exchange 2010, you may encounter a Max EWS Request error:

Modify web.config

Use the following steps to resolve a failed restore:

1. Log into your Microsoft Exchange 2010 Server as the administrator, and navigate to the Program Files > Microsoft > Exchange Server > V14 > Client Access > exchweb > ews folder, and create a copy of the file web.config:
   

   Creating a copy of the web.config file allows you to revert to your original settings in case you encounter issues during resolution of the restore error. 

2. Open the original web.config file using Notepad running as the administrator.
3. In Notepad, go to Edit > Find, and enter max in the find what field:
   
4. Click Find Next until you locate the following line of code:
   <httpsTransport maxReceivedMessageSize="13600000" authenticationScheme="Anonymous" maxBufferSize="81920" transferMode="Streamed" />
5. The value maxReceivedMessageSize="13600000" represents a maximum attachment size of 13MB. Therefore, any attachments over 13MB cannot be restored. Change this value to a larger value to handle the largest attachment failing to restore, for example, replace 13600000 with 53600000 which allows for attachments just over 50MB:
   
6. Click Find Next until you locate the following line of code:
   <httpsTransport maxReceivedMessageSize="13600000" authenticationScheme="Anonymous" maxBufferSize="81920" transferMode="Streamed" />
7. Replace 13600000 with the same value you entered in step 5 above, for example,  53600000 .
8. Click Find Next once again until you locate the following line of code:
   <requestLimits maxAllowedContentLength="13600000" />
9. Replace 13600000 with the same value you entered in step 5 above, for example, 53600000 .
   Click File > Save, and close Notepad.

 Run appcmd

1. Log into your Microsoft Exchange 2010 Server, and at a command prompt, change the directory to the inetsrv folder:
   cd c:\windows\system32\inetsrv
2. At a command prompt, run the appcmd command using the new size limit value you entered in the previous section:
   appcmd set config "Default Web Site/ews" -section:requestFiltering -requestLimits.maxAllowedContentLength:53600000
   
3. Close the command prompt.
4. Open Services and restart the following services:
   • Restart IIS Admin Service:
     
   • Restart Microsoft Exchange Transport:
     

Barracuda Backup Restore

1. Log in to your Barracuda Backup web interface, and restore the messages that originally failed.
2. Messages should now restore without any errors. However, if you continue to encounter errors when restoring large messages, continue to the next section, Configuration Settings.

Configuration Settings

Verify Exchange Management Console Settings 

1. Log in to your Microsoft Exchange 2010 Server, and open the Exchange Management Console (EMC).
2. Expand Organization Configuration, click Hub Transport, and click the Global Settings tab:
   
3. Right-click Transport Settings, and click Properties:
   
4. Verify the Transport Limits settings are large enough and listed correctly, then click OK.
5. In the EMC, expand Server Configuration, click Hub Transport:
   
6. Right-click on the Client Receive Connector, and click Properties:
   
7. Verify the value in the Maximum message size (KB) is large enough to accommodate message restore.
8. Right-click the Default Receive Connector, click Properties, and verify the Maximum message size (KB) is large enough to accommodate message restore.
9. If you modified any settings in the preceding steps, go to Services and restart both IIS Admin Service and Microsoft Exchange Transport services.

Exchange Management Shell

1. Open the Exchange Management Shell, and enter the following command:
   get-tranportconfig:
   
2. Verify that the following settings are large enough and listed correctly:
   
   • ExternalDsnMaxMessageAttachSize
   • InternalDsnMaxMessageAttachSize
   • MaxReceiveSize
   • MaxRecipientEnvelopeLimit (shown in KB)
   • MaxSendSize
3. If any of the values need modification, run the following command:
   Set-transportconfig -<setting to be changed> <size>
   For example:
   set-transportconfig -MaxSendSize 50MB
4. If you modified any values through the Exchange Management Shell, go to Services and restart both IIS Admin Service and Microsoft Exchange Transport services.