Exim Configuration - message_size_limit issue

I have WHM 11.34.0 (build 9) running on a CentOS 5 box and I am trying to increase the default message size limit of 50MB to 100MB as we have a client with specific needs for sending and receiving unusually large files. I have added the message_size_limit variable using the Exim Configuration Manager > Advanced Editor and set the value to 100M. I have restarted Exim a number of times, but I still get a 552 response from Exim saying the maximum mail size is still 50MB when I try to files greater than 50MB. Am I missing another configuration option somewhere that must be set for this to work? I have checked the exim.conf file to ensure that the setting is there and it appears at the top of the file.

Any help would be appreciated.