If you are running IIS7 and Windows 2008, you may need to increase WCF settings:
- Open Windows Explorer.
- Navigate to C:\Program Files\Microsoft\Exchange Server\ClientAccess\exchweb\ews
- Open the file Web.Config in a text editor like Notepad.
- Find all XML tags starting with maxReceivedMessageSize=
- Change existing values to maxReceivedMessageSize="104857600"
- Save the file.
- Open a Command Prompt (cmd.exe).
- Type: cd %windir%\system32\inetsrv
- Type: appcmd.exe set config "Default Web Site/ews" -section:requestFiltering -requestLimits.maxAllowedContentLength:104857600
- Run: iisreset