ActiveSync cannot send large file on Exchange Server

To resolve this issue with iOS devices, we typically recommend increasing the Maximum Request Length parameter on the web.config file for ActiveSync on the Client Access Server(s).

  • On the CAS servers, browse to the web.config file (under the ClientAccess\Sync folder)
  • Open the web.config file
  • Modify the <httpRuntime maxRequestLength=”10240″/> parameter to a higher value to something higher, such as 15360 (15MB)..
  • Save the updated web.config file
  • Restart IIS (IISRESET)

Configure client-specific message size limits