I have spent most of the day trying to figure out how to file with IRIS through the information return system.  Apparently, it doesn't I am learning.  EasyAcct IRS does not state that, but IRIS says it accepts csv files.  The file I created to e-file the 1099s with the software was a DAT.  I cannot find either how to export the 1099 file to a csv instead of a dat.  So, I am at a frustrating loss as well.