18.1MB is bigger than any web email can handle. Yahoo, Gmail, Hotmail, are all in the 4 to 5 MB range for a single file.
I have no idea about uploading it here. There is probably a limit for attachments, but I don't what it is.
Here are your options as I see them-
#1) Join the Yahoo group and upload the file there. You can then advertise here, and anyone who is not a member of the yahoo list can join to get your design. You can also, of course post on the Yahoo list to let everyone there know there is a new design for them to download and play.
#2) PM Ziroc and ask him if he is still willing to host designs for DC. If yes, he can tell you where to upload, if no, then choose another option.
#3) Use a free file storage site such as ShareCG, DivShare, etc. (there are a bunch of sites, but I"ve personally used these two and was quite happy with them).
#4) Start a new thread asking if anyone here can host your demo.
