Why would you want to have a zip? CS2D can't extract it automatically and you shouldn't use CS2D for file distribution.
(By the way: CS2D compresses all files it sends via file transfer. It's not necessary to manually compress them as zip)
In fact many people who are coming into my server are not seeing the gfx << and want when they come on my server automatically download and do not know how to do @DC
Please never ever reply in a post AND send a PM at the same time because I read both and now I also answered both which is simply pointless and annoying. Also never continue a thread in a PM! Always keep it public in the forum unless there is a real good reason to do it in private.
Clients can specify a maximum download size for transfers in their settings. I think 250kb is the standard value. Keep your files below that.
Please note that downloads can also completely be disabled. You can't force people to download your files. You could check it later with a script though and kick them from your server or do other stuff.