FILE_DATA_PORTSvariable into your snort.conf file.
We are increasingly using this variable across multiple categories to be able to more thoroughly cover file based attack vectors, and will continue to use it, so make sure you are using the snort.conf provided by the VRT here:
Which includes the
# List of file data ports for file inspection
portvar FILE_DATA_PORTS [$HTTP_PORTS,110,143]