Changing the Maximum Attachment Size

The default maximum attachment size is 4 MB. That limit can be changed by editing the web.config file. Changing the maximum attachment size applies system-wide to attachments made on the document child forms.

You must be an administrator on the web server to complete this task.

You should consider the available storage on the server for attachments before increasing the maximum file size.

Use the following steps to increase the maximum file size for attachments:

  1. Locate the web.config file for the iWeb instance you want to change, and open the file in a text editor.
  2. Locate the <system.web> node and the <httpRuntime> node.
  3. Edit the maxRequestLength attribute as follows:
    • The value of maxRequestLength is the maximum number of bytes permitted for an attached file.
    • You can specify a value between the default of 4000 (4 MB) and 102400 (100 MB).

    For example:

    <httpRuntime maxRequestLength="102400" />
    4.    
  4. In the <system.webServer> node add a section to permit the attachment request for the size specified in step 2. The following example shows the section with the maximum attachment size specified. 
    <security>
      <requestFiltering>
        <requestLimits maxAllowedContentLength="102400" />
      </requestFiltering>
    </security>
    5.    
  5. Save your changes.
  6. Stop and restart the IIS server to apply the changes immediately, or the changes will be applied at the next IIS server restart.

For more information about this web.config option, see http://stackoverflow.com/questions/6327452/which-gets-priority-maxrequestlength-or-maxallowedcontentlength